Archive of Our Own ^beta

Atsumu has always been prone to starting fights. Whether that stems from growing up with an alpha twin brother that he could challenge at any given moment or if it’s just his personality, Suna doesn’t really know. It’s something that takes most alphas some time to get used to when they meet him first; how Atsumu always seems to challenge, always seems itching to test them. 

Sometimes, Suna thinks, it’s almost as if he wants to be settled like a pup, like he wants someone to hold him down by the neck and make him submit. And when he watches Atsumu challenge Meian during a practice match and he sees Atsumu relax with an almost lustful expression on his face when the alpha puts his hand on the back of Atsumu’s neck, the only thing that comes to mind is: “ Interesting.”  

Because while Suna is also an alpha, he doesn’t really care about dynamics. Not when it comes to how he treats his team mates (everyone gets the same respect, everyone gets the same sass and everyone is held to the same standard), not when it comes to bedroom partners. All that matters to him is whether he likes you or not. Or whether you have a pretty face or not. 

Luckily for Atsumu, he has both. 

When Atsumu gets into another stare down with Washio during a match a few weeks later and Suna sees his shoulders drop in disappointment when he comes out victorious again, a plan forms in his head.

“Atsumu, come over to mine after,” he says when they shake hands at the end of the match. “Wanna show you something.” 

It’s easy to get the alpha to agree, Atsumu’s aways in the mood to hang out with Suna. And after spending a few too many hours sleuthing on the internet and talking to Motoya’s mother who works in a fertility and gender clinic, Suna thinks he has all the knowledge he could possibly want on what he has planned. Of course, it’s all based on speculation, Atsumu’s predicament. But Suna wouldn’t be Suna if he wasn’t curious to the point of almost being intrusive, and self-assured to the point of nearly being arrogant. He’s very confident he’s got this right. 

Atsumu of course starts teasing and testing Suna the moment they are out of the gymnasium, like he does with almost everyone. Suna’s used to it, never letting Atsumu rile him up too much that one of them loses control. He’d like to, secretly. The tension between them has always drawn him in, has always made his fangs itch. 

So when Atsumu jostles him when they both try to step into the genkan at the same time, Suna just copies Meian’s movement and grabs Atsumu’s neck. There’s an addicting thrill that zips down his spine the moment his skin makes contact with Atsumu’s, and he can feel his friend tense before becoming nearly pliant at the touch. 

“Who said you could go first,” he murmurs near Atsumu’s ear, letting his breath tickle him. Suna revels in the way Atsumu seems to shiver. 

“I did, because I’m clearly taller than you.” Both of them know that is a lie, Suna being about two centimetres taller.
“ Sure ,” Suna humours him, “but this is my den. So I go first.” To add weight to his statement, he tightens his grip on Atsumu’s neck. He narrows his eyes when he sees a hint of redness appear on Atsumu’s cheeks. 

He lets go, fully expecting Atsumu to barrel right into Suna’s apartment. But to his surprise – and satisfaction – Atsumu stays right where he is, shoulders slightly drawn up, cheeks red and eyes wide. Suna is tempted to reward him with a “ Good boy ” but stops himself.

“Make yourself comfortable like usual, I guess,” he tells Atsumu, something that’s completely unnecessary after their years of friendship. It slips out without his consent, nerves suddenly scratching at his stomach as he walks to his kitchen. “Want anything to drink?” Atsumu had only started walking after Suna had told him to make himself comfortable, something that hadn’t gone unnoticed. 

It really is obvious, now that Suna knows what to pay attention to. 

As he sets down their drinks – Atsumu wanted Mitsuya soda, no surprise there – he begins phase one of his plan.
“Atsumu,” he starts. “You do that on purpose, don’t you?” His friend looks confused for a moment, brows furrowing as he halts the hand that’s twisting open the plastic bottle. 

“Do what on purpose,” he asks when he doesn’t seem to be able to figure out what Suna means. 

“The bratting,” Suna says. “Acting up. Challenging other alphas. Behaving like a little shit,” he adds when Atsumu’s brows only furrow more. 

“I have no – ,” Atsumu starts to rebuke, only to be shut up when Suna lifts a finger. 

“There’s no need to feel ashamed about it, there’s nothing wrong with wanting to be put in your place.” He really hopes he’s got it right, because Suna can see the conflicting emotions flicker behind Atsumu’s eyes as he works his jaw. 

He realises he’s right when Atsumu averts his eyes and lets his head drop in submission, though only a little. 

“How did you find out,” he whispers after a beat of silence, hands nervously playing with the plastic label around the bottle. 

“It was obvious when you almost moaned when Meian grabbed your neck,” Suna teases and he takes delight in the way Atsumu flushes. 

“All those years I thought you were just a brat, an insufferable alpha who wants to prove to everyone how strong he is. How powerful he is. I couldn’t have been more wrong.” Atsumu takes a shaky breath and lifts his head, fire in his eyes as he meets Suna’s. 

“So now what, gonna make fun of me and tell everyone Miya Atsumu’s an alpha who wants to dominated, who wants to handled like an unruly pup? Dick move Sunarin,” he spits. It sounds like an insult again, like a challenge to prove his strength again. But Suna knows better know. 

So instead of challenging back, Suna allows his scent to grow thicker as he rises to his knees, towering over Atsumu. It’s delicious how his eyes widen for a moment before hardening again, the alpha falling back into his old pattern of fighting back. 

“No, I’m going to help you.” Atsumu blinks a few times, mouth opening and shutting immediately again as he processes what Suna said.
“Help me,” he croaks, and it is so much more vulnerable than Atsumu has ever sounded. Suna feels his desire stir. 

He plants his hands on either side of Atsumu’s head, caging him against the sofa’s back rest as he hovers above him.
“Have you heard of bitching,” Suna asks lowly and he rolls his eyes when Atsumu starts sputtering.

“Bitching? Ha! You mean that ridiculous thing where an alpha gets fu – when an alpha is dominated by another alpha?” He shuts Atsumu up with a soft bite to his neck that the alpha definitely bucks his hips at.

“Close, but not entirely right,” he tells Atsumu when he pulls back, pride swelling at his blown pupils. “Bitching is when an alpha is forced to transition into an omega, with the help of another alpha. Your body will change when exposed to only alphas for long enough, especially when combined with their sperm and rut pheromones. Fascinating, isn’t it, how we have come to evolve to the point that our bodies will adapt like that. Something with nature making sure there’s always a fertile partner available.” 

That is not exactly how it works, there’s a lot of science behind how potent alpha sperm, from a rut for example, and enough exposure to only alpha pheromones can turn one into an omega, but Suna doesn’t want to bother with all those complicated medical terms right now. He wants to see how Atsumu responds. 

“So you – I can… You wanna turn me into an omega,” he stammers, cheeks red again and eyes so comically wide Suna finds it cute. 

“No, you want that. To be turned into an omega.” Atsumu doesn’t say anything, only clamps his jaw shut with a click as he turns even redder.

Bullseye. If Suna had placed a bet on this, he would have been filthy rich now.

“And you’re going to help me turn into an omega,” Atsumu says breathlessly as he avoids Suna’s eyes. “Because… Why, actually?” Suna huffs out a laugh and moves back, falling onto the seat of the sofa again. 

“Because I think you’re hot and I’ve been wanting to fuck ya for ages.” It really shouldn’t be so satisfying to rile Atsumu up, but it is. 

Suna is already addicted to the way he blushes, how he fidgets, how he nervously avoids his gaze. It makes him want to tilt Atsumu’s chin up to force him, makes him want to kiss Atsumu senseless until he’s panting and writhing and wet beneath him. It makes him want to ruin him. With consent, of course. 

He tests out the boundary by starting with the first thing, getting Atsumu to look at him again. The alpha gasps when Suna grabs his chin but doesn’t resist when he lifts it so he’s looking Atsumu in the eye. 

“Wouldn’t you like that, Atsumu? Having a powerful alpha on top of you, pinning you down and slowly fucking you open?” The hitch in Atsumu’s breath tells him yes, even when Atsumu tells him no. 

“Stubborn, aren’t we,” Suna taunts, tightening his grip on Atsumu’s chin as he leans closer. “That’s alright, I can handle you. I’m not backing down from this unless you tell me to.” He knows he’s won when Atsumu doesn’t tell him to stop, doesn’t push him away or curses at him. Atsumu proves him he’s right with the soft whimper that falls from his lips, even though his nails dig into Suna’s thighs. 

“What, think you can take me,” Atsumu bites out and Suna smirks. 

“I know I can take you. And I know you want me to.” He wants to kiss him, so bad. “You’d take it so well, you’d submit so well.” Atsumu growls, pushing forward and slotting their lips together in an angry mess of teeth, tongue and spit. Suna feels almost delirious. 

“Bet ya can’t handle me,” Atsumu pants against Suna’s mouth, eyes murky with want. 

“Bet ya I can.” He’s not one to back down from a bet and Suna knows it. That’s entirely what this whole plan is based on: Atsumu’s inability to take no for an answer. But he needs an answer, a confirmation before he moves on. Consent is sexy, after all. “Will you let me?” 

The minute or so that it takes Atsumu to respond feels like eternity, Suna’s heart beating against his ribs almost painfully. He wants this, wants Atsumu like this. To finally have him at his mercy, to finally be allowed to touch, to taste . The storm that is Atsumu has had him in a vice like grip for too many years, his scent has been driving him wild for as long as he can remember. But he won’t take if he’s not allowed, won’t taste if Atsumu doesn’t agree. Because he doesn’t want to fuck up anything between the two of them. 

“If I say yes, will you stay? Will you help me through it?” The question is heavy, hangs between them like the humid before a thunderstorm. Suna can almost taste the tension in their scents.

“You want me to bitch you,” Suna asks and he hates how unsure he sounds for a moment. He wants to be proud, wants to be powerful for Atsumu, show that he’s a worthy alpha for this. But he also wants to be certain this is what Atsumu wants, that Atsumu wants it to be Suna who bitches him. He might have said that he’d do it when he started this conversation, but Suna had never once thought that it was set in stone. If Atsumu had asked for another alpha to do it, Suna would have let him go. 

Atsumu looks at him, seemingly calm except for his eyes where Suna can see him fight his inner alpha. 

"Yes. I want you to bitch me,” the release finally comes and Suna almost lunges forward, pushing Atsumu down with his body. He’s met with a growl and sharp nails digging into his skin through his shirt and shit if it isn’t the hottest thing he’s ever felt. 

Kissing Atsumu is addictive, the way he bites, licks and fights against Suna’s lips. The taste is sweet though, sweet like honey and Suna wishes he’d never have to stop.

“Off,” he tells Atsumu as he pulls on his shirt. Atsumu bares his teeth. 

“Don’t boss me around.” Suna huffs, eyes narrowing as he pushes his legs over Atsumu’s. 

“What’s that, is the pup misbehaving,” he goads, pulling on the shirt again. “Off,” Suna repeats, voice sterner this time.

The flex of Atsumu’s muscles at the command has Suna’s mouth watering and he licks his lips. 

“No,” Atsumu challenges and Suna can feel himself grinning. He drops the hem in favour of fisting just below the collar of Atsumu’s shirt, pulling him up again to show off his strength. 

“Then I’ll just do it myself,” Suna says. There’s a silent challenge in the way Atsumu looks at him, and Suna wants.

He grabs Atsumu’s wrists, hoisting them above his head and pulling the shirt up and off before the alpha can fight it. Atsumu is breathing erratically when Suna lets his wrists go and he fully expected the way the alpha shoves him back against the sofa, switching their positions with his teeth still bared. 

“Now was that so hard,” Suna taunts, a lilt in his voice. His alpha is restless, clawing against him to fight back and take, take, take.  

Patience, Suna tells it, soon.  

“Don’t tell me what to do,” Atsumu repeats, voice a little hoarse as he pants out hot breaths. His eyes are pleading though, so obviously showing of the desperation he feels now that Suna knows the signs. 

“Oh but I think I will,” he tells Atsumu, lifting a hand to trail up the alpha’s back to his neck. “I’ll boss you around as much as I like, because you’ll be my little omega from now on. Meant to be told what to do, meant for me to play with. So be a good pup and behave, hm?” 

He expects Atsumu to fight it again, to snarl, growl or bite at him again. But he watches with hunger as Atsumu’s eyes flutter closed at the touch again and he lets out a whine that has Suna feeling so starved, like he’s never eaten before. The kiss he presses against Atsumu’s lips is a filthy one, prying his mouth open and licking into it harshly. He moves his hand from Atsumu’s neck into his hair, pulling it roughly to the side to angle their heads into a better position. 

Atsumu rewards him with a moan, hands flying to Suna’s hips where his nails dig into his flesh again. 

“ Shit Sunarin, just like that,” Atsumu pants when they pause for air. He looks debauched, lips swollen and slick with spit, fangs longer than they were minutes ago. Suna’s alpha roars. 

“Yeah, you like that? Like it when you’re manhandled like that?” 

Again he expects Atsumu to fight back, but again Atsumu whines, chasing Suna’s lips. He thought a fighting, bratty Atsumu turned him on beyond reason, but that was before he got a taste of submissive, begging Atsumu. 

“Please Sunarin, I want – I need – ,” he pants, already sounding winded. 

“What do you want pup, tell me,” Suna teases, tugging on Atsumu’s hair again.

He growls, trying to bite down hard on Suna’s lip. It earns him another sharp tug, Suna forcing his head to tilt backwards and bare his throat. Atsumu thrashes, legs shifting as he tries to find purchase so he can fight back again. 

“Tell me,” Suna growls back, watching Atsumu’s Adam’s apple bob as he swallows thickly. 

“Want ya to take me, need ya to take me,” he bites out, sounding anything but begging and sweet.

“You can do better than that. Be nice when you ask for something.” There’s a rush that heats up his body when he chastises Atsumu and the alpha stops moving for a moment, scent spiking. “Oh you like that? Beg for it then, like the needy slut you are. Beg your alpha,” Suna continues, hand still tightly fisting Atsumu’s hair. 

There’s a war going on behind Atsumu’s eyes, he can see it. Anger and something softer keep flittering in them, replacing one another until finally the heat dies out and his body relaxes. It feels like the only thing keeping the alpha upright is Suna’s iron grip. 

“Please,” Atsumu whispers. “Please alpha.” 

The growl that rips from Suna’s throat is near feral, body wild with desire as he pulls Atsumu to his feet by the hand, dragging him to his bedroom, to his den. With impatience, he sheds his own shirt and undoes his jeans, turning around to order Atsumu to do the same. 

“Take it all off,” he commands, gaze hungry as he takes in the sheen of sweat on Atsumu’s torso. The other moves slowly, stopping when his fly is undone. 

“Hurry up,” Suna snarls when Atsumu doesn’t continue, at which the alpha’s head snaps up. Atsumu’s teeth are bared again, the beginning of a animalistic reply forming in his throat. With three quick strides Suna is in front of him, and with two more he has Atsumu pinned to a wall. 

“Off,” he demands harshly, giving a hard tug on the waistband of Atsumu’s jeans. They fall down to halfway down his thighs. “Don’t disobey your alpha,” Suna warns lowly, letting his lips ghost over Atsumu’s now bared neck. The other gasps and then whimpers, hands reaching out to grasp but stopping mid-air. 

“Want to touch you,” Atsumu begs, begs. “Can I touch you, please .” 

It’s such a power trip, to have Atsumu fighting against him first only to then submit and beg for it. Suna thinks Atsumu’s perfect, the perfect challenge for Suna to take apart and ruin. 

“Go on then, touch your alpha. Show me how well you take care of me.” 

Hot kisses are pressed to Atsumu’s neck, painting a path down to his collarbone with red marks and indents of Suna’s teeth that leave Atsumu a whimpering mess against the wall. 

“Please,” Atsumu begs again and Suna grabs his wrists to force his hands onto Suna’s back. The touch is searing, almost burning Suna when the alpha claws at his back. 

“That’s it, that’s it,” he pants against Atsumu’s neck. His scent is overwhelming, alluring to Suna as he licks Atsumu’s scent gland. Nails scratch painfully hard down his back, Atsumu stepping forward to force Suna back. Out of reflex almost, Suna’s hand flies to Atsumu’s throat and the alpha stops, eyes downcast again. 

“Get on the bed,” Suna says lowly, voice rough. He pushes against Atsumu’s shoulder for good measure, watching the alpha stumble towards the mattress. Atsumu shudders when his body meets the sheets, no doubt affected by the lingering smell. 

“Now, you’re going to be good and get undressed for me. I’m not going to ask nicely again,” he warns, dragging his nails down Atsumu’s back with a little more force than would count as a gentle scratch. Red stripes follow in their wake. 

Atsumu hurries to take off his jeans and boxers fully, falling onto his back. Suna drinks in the sight of Atsumu’s cock, heavy and hard between his legs. 

“Good boy,” he rewards this time and watches in fascination as it kicks. 

Suna kicks off his own jeans and boxers, smirking at the way Atsumu licks his lips when his eyes land on Suna’s cock. 

“Like what you see,” he says and Atsumu nods greedily. The alpha is pliant when Suna crawls over him, lets him kiss him a little more gently. Suna drags his tongue over Atsumu’s teeth, curls it around his tongue and runs it over the roof of his mouth. 

He’s panting and whining in minutes, arching beautifully to push himself closer to Suna with each tug on his lips. 

“So desperate,” Suna murmurs and Atsumu moans. “So desperate for me.” He trails his hands down Atsumu’s sides, reaching for his hips and squeezes, testing out the waters. 

“Have you ever touched yourself,” he asks when Atsumu only keens, hands tangling in Suna’s hair. “Played with yourself? Used a toy on yourself?” Atsumu curses as Suna’s hands dip lower, grabbing the undersides of his ass cheeks. The alpha lets out a weak growl when Suna’s thumb briefly slips between them. 

“Yes,” Atsumu pants, “Yes to all of it.” And fuck if that isn’t something Suna would want to see one day, Atsumu spreading himself open to fuck himself silly on a toy.

“Shit Atsumu, you’ve been begging for it haven’t you,” Suna groans. “Been waiting for someone to find out, for someone to pick you apart and piece you back together.” 

“Sunarin, please,” Atsumu pleads, hands tugging harshly in Suna’s hair. He moves his hands away, reaching over to his night stand where he keeps lube for when he takes home a beta. 

“Has anyone fucked you yet,” Suna asks when his slick fingers circle Atsumu’s hole. “Anyone else touched you here yet?” Another weak growl from Atsumu when Suna pushes in, then a breathless “ No ” that sends Suna’s heart in overdrive. “Shit baby,” he babbles, pet name slipping out on accident, “Let me make this good for you.” 

He takes his time fingering Atsumu open, slowly moving only one finger in and out for a long time. Atsumu’s alpha is restless, he can tell, his friend growling and baring his teeth every time Suna pushes in a little too roughly. It’s one thing to touch there by himself, another thing entirely when another alpha is doing it. 

“That’s it, that’s it baby,” Suna murmurs against Atsumu’s thigh, kissing him and nipping gently. “You’re doing amazing for me.” Atsumu whines, back arching lightly. “Want me to add another one?” He hears Atsumu gasp and feels him clench down on his single digit. 

“Yes, please. Want it – haahh – need it Sunarin.” 

Regardless of what Atsumu wants, his alpha is still fighting it, making him snap his teeth loudly when he feels the other finger against his hole. He manages to rein himself in again, Suna’s second finger slipping in. Atsumu moans, a breathless little thing and Suna drinks it in as he kisses him.

“Sound so needy for me, so desperate for me.” 

“Want more, give me more.” 

This time, Atsumu takes it without fighting, instead throwing his head back as he welcomes Suna’s touch. It’s so hot, so unbearably hot and Suna really hopes he will be allowed to fuck him. He’s been carefully avoiding touching Atsumu’s prostate too much, not wanting the alpha to come yet. Suna’s dizzy with his scent and his skin feels on fire. 

“Look at you, taking my fingers so well. You were made for this, made for taking.”
“Yes, yes,” Atsumu moans, rutting his hips down towards where Suna’s scissoring him open. 

“I’ll turn you in such a perfect omega Atsumu. Bitch you so well so you can take my knot, want to take my knot?” He’s feeling impatient, cock heavy and hard between his legs. Mostly focussed on Atsumu he has neglected it, leaving it leaking onto the sheets.

“Ready for you, want ya in me Sunarin.” That’s the last bit he needs, restraint finally out the window and he lines himself up. He expects Atsumu to fight again, or at least to tense, but instead he finds the alpha reaching out to pull him in. 

It’s tight, tighter than anyone Suna has fucked before, hotter than anyone Suna has fucked before. Atsumu twitches and squeezes around him and Suna can’t stop the groan that falls from his lips, burying it against Atsumu’s neck.
“So tight,” he pants and Atsumu mewls. “Love it Atsumu, love how you feel around my cock.” 

“Good, so good Rin.” Sharp nails claw down his back, making Suna hiss. He takes it as a sign to start moving.

His pace is slow and steady as he keeps a very careful eye on Atsumu below him. So far the alpha is doing well, face blissfully relaxed. It looks even better than Suna could have ever imagined, and he has imagined this countless times. 

“Shit look at you baby. So pretty with you face all flushed. Do I make you feel good, alpha’s cock feel good?” Again nails scratch over his back as Atsumu clenches. He locks his ankles behind Suna’s hips and pushes him closer, urging him on. 

“Faster Sunarin, fuck - ,” he pleads. Suna snaps his hip forward faster, harder, making the alpha beneath him moan shamelessly. Atsumu seems to be enjoying himself thoroughly, cock leaking onto his stomach and it makes Suna wonder if he can come untouched like that. The thought makes him growl, teeth nipping dangerously at Atsumu’s neck. 

“Gonna come like this, untouched with just my knot in you?” It should feel wrong, but to Suna it feels like everything he ever dreamed of. Atsumu’s scent all around him, sweetened with arousal. He can’t wait to find out what Atsumu’s omega scent is like, if it would be even sweeter. 

“Yes, want to come on your knot like this, want to be good for you,” Atsumu moans, voice strained as he starts chasing his orgasm. 

“Yeah? Then come for me on my knot, like the needy omega you are.” 

Suna isn’t certain that his words are what tip Atsumu over the edge, but he likes to think so as he feels him clench and flutter. It doesn’t take much for Suna to come, tight heat around him making his knot inflate as he fills Atsumu. 

He doesn’t force his knot in, lucid enough to realise that would only cause the alpha more pain than pleasure, even if Atsumu whimpers in disappointment. 

“Soon,” he promises when he’s come down from his high a little, pressing kisses to the tears in the corners of Atsumu’s eyes. “Soon you’ll get my knot.” 

On wobbly feet, Suna makes his way to the bathroom to get a wet towel. Atsumu lets himself be cleaned up, and then lets Suna push the trickle of come that escaped back into his hole. 

Atsumu smiles at him, holding out his hand and Suna joins him in bed again.

“Thanks Sunarin,” he sighs, burying his face in the crook of the alpha’s neck. “Always wanted to do this, ya know.” The confession maybe shouldn’t be a surprise, but it is. “Had a crush on you for years. Never thought it’d be like this though.”

They talk about the details after that, something they maybe should have done before. Suna explains the process in detail, showing Atsumu the articles he had found himself. He tells Suna that he’s always thought he should have been an omega, but that he never thought there was an option to become one. It makes Suna ache, realisation that Atsumu could have long been his mate already if they had just spoken about this.

The only problem they find is Atsumu needing to be fucked regularly for the change to happen, and that requires moving. With Suna in Shizuoka and Atsumu in Osaka, they both decide to go apartment hunting in Nagoya. Until then, Atsumu will travel back and forth between the two cities for a while. His team is informed and everything is set into motion. 

Suna feels like he’s in heaven the following weeks, drowning in pleasure and Atsumu’s scent that now lingers all around his apartment. The sex is great and Atsumu seems to be having an easier time every time they try it, his inner alpha submitting quicker every time Suna fucks him. 

His demeanour is changing too, slowly Atsumu’s hot-headedness seems to be fading. He is no longer riled up easily, stops acting out during practice and matches, doesn’t stare down other alphas anymore. The team seems happier even, everyone around him also settling better with the new version of Atsumu. 

Suna has caught him a few times in front of the mirror, Atsumu inspecting every bit of his body to see if there are any changes. Every time it happens, Suna tries to distract him, hands running over the expanses of the alpha’s skin as he kisses his neck and shoulders.
“It’ll come,” Suna tells him. “Your body will change soon enough.” It always helps, distracting Atsumu with sex, and slowly the changes do become obvious. 

The first thing that is noticed is the change in his scent. It keeps the sweet undertone that normally only shows during sex, making Suna go crazy with want the first few days it starts to show. Hinata comments on it too when Atsumu shows up for practice, complimenting him on the new scent. Atsumu preens, taking delight in the way Suna cannot seem to stop smelling him. 

Next to change is finally his body, hips filling out and legs getting slightly softer. Even his chest becomes less buff, thin layer of fat settling over them. It’s a change that also brings some discomfort as bones start to shift and change. More than once does Suna spend his evening massaging and gently kneading the painful muscles, putting warm compresses over the parts where massaging won’t help. It makes him feel a strange sense of primal pride, alpha satisfied that he is providing for a mate. 

Suna tries to stop that train of thought right there, but fails embarrassingly and he starts to overthink it spectacularly. 

It’s during sex one time that he messes up, telling Atsumu he’d mate him during dirty talk. Suna immediately stills, cheeks aflame as he realises what he said. Atsumu doesn’t seem to mind the slip up, if the spike in his scent and the needy whine are anything to go by. 

It’s a topic they avoid afterwards though, Atsumu probably thinking it to be a heat of the moment thing and Suna desperate to keep his secret a secret. 

The pain in Atsumu’s lower body has been constant, so he immediately notices when it has gone. Suna wakes up to Atsumu sucking his dick and then he proceeds to fuck the alpha silly after Atsumu tells him the pain was gone. But he seems almost disappointed when he doesn’t slick. 

Hormones are blamed when Atsumu cries after, apologising to Suna for taking so long.
“Haven’t you gotten sick of me yet,” he asks while rubbing away the tears that don’t want to stop. “Surely there is someone you want to be with.” Suna doesn’t answer, instead holding the other closer as he releases his scent in an attempt to soothe. 

When Atsumu finally starts slicking, there’s no stopping them. It’s conveniently timed to be right before a long weekend off, a weekend that turns into a marathon fuck fest.

“Shit Atsumu, look at you,” Suna marvels as Atsumu is pressed face down into the mattress. Their new apartment has a bigger bedroom and also a bigger bed, a place where Atsumu has started to build a nest. He also started one on the sofa, collecting pillows and a blanket to keep him warm when they watch TV. 

“Look at how you’re slicking for me. Want to taste it,” he murmurs against the swell of Atsumu’s ass. The scent is intoxicating, still getting sweeter with every week that passes. Atsumu mewls when Suna licks a stripe over his hole. The taste is even better, making Suna moan as he licks and tastes. Atsumu is quivering before him, thighs shaking. 

“Alpha please,” he begs, having started to call Suna that most of the time. It’s a sign how his brain is changing along with his body. “Want alpha’s knot, want it so bad.” 

Suna sits upright with a growl, grabbing Atsumu’s hips and digging his nails into the now supple flesh. All the hard edges are gone, making Atsumu even more beautiful to him.
“Yeah, want me to give you my knot today? Think your needy little hole can take it?” 

“Yes, yes I can take it, I want to take it,” he babbles, trying to reach behind him to spur Suna on. 

Atsumu had always been tight and hot, but with the added slick it feels unreal. Suna nearly comes the moment he pushes in, Atsumu’s hole greedily clenching around him.
“Oh my god,” he gasps, hands raking over Atsumu’s skin as he tries to fight off the orgasm. “Shit Atsumu you feel amazing baby.” 

He doesn’t last long, dragging Atsumu over the edge with him by fisting his cock. It’s a little unfair, but Suna makes up for it by pulling another orgasm from him with his tongue. The last step in their journey is helping Atsumu through an actual heat, after which his body will be entirely transitioned. 

They haven’t spoken about what happens after, whether they move back to their old cities, whether they will stop sleeping together. Suna knows that’s not what he wants, his fantasies and dreams at night now often consisting of mating with Atsumu, living together in the country side with Atsumu, maybe even breeding Atsumu. 

But he doesn’t dare to ask, doesn’t think it’s even his right to ask. He had offered to help Atsumu with the bitching out of interest for himself, wanting to sleep with the alpha. Of course he had known about his own feelings, but bitching someone doesn’t mean you are entitled to become their mate. And for some reason, Suna just feels it would be wrong to even start that conversation. 

So he doesn’t, and instead continues to fuck Atsumu into their mattress in their nest every night, never once tiring of the sweet, sweet scent that now seems to cling to him all the time. 

When he returns home late from a team meeting a few weeks later, he can tell something is wrong before he even steps further into the house. All the lights are off, Atsumu’s shoes haphazardly strewn around in the genkan, coat lying on the floor. Suna follows the line of scattered clothes until he reaches their bedroom door, finding the ventilation to be on full blast and Atsumu naked and writhing in the nest. The closet has been raided and most of Suna’s jumpers have ended up tucked between the pillows. His blood immediately runs hot. 

“ Atsumu ,” he murmurs reverently as he steps closer to the bed. “Atsumu, baby, are you in heat.” It’s a rhetorical question, because even with the ventilation on Suna can smell the potent pheromones in the air. It drives him wild, making his alpha restless with need. Claim, claim, claim, it chants. Mate, mate, mate, it demands. Suna wants to agree. 

“Hurts,” Atsumu whines when he realises Suna is standing next to the nest. “Alpha, hurts. Want your knot alpha,” he begs.
“Yeah, want alpha to fuck you through it,” Suna asks as he steps even closer, one hand wiping away the sweat on Atsumu’s brow. “Can I get into the nest?” 

The alpha – no, omega – nods and shifts a little, making room so Suna can join him. 

“Such a pretty nest,” Suna tells him once he’s at Atsumu’s side. “You did so well for alpha.” 

Atsumu is drenched when Suna reaches for him, hole leaking slick eagerly as he fingers him open. There’s no reason for it, Atsumu is loose enough that he could take him like this. But Suna wants to savour it, wants to enjoy this first as alpha and omega. 

His slick is even sweeter than usual, reminding Suna of the finest honey, the sweetest candy and he doesn’t think he’ll ever be satisfied with gummies or chocolate anymore. He’s getting impatient, listening to the way Atsumu moans and whimpers whenever Suna plunges his fingers into his hole. 

“Hurry up alpha, hurts, want your knot in me already,” he complains, pushing his hips further back. 

Suna takes off his clothes then, throwing them somewhere into the nest with the rest of his wardrobe and lines himself up. He holds his breath, not entirely prepared for what he’s about to do and a little nervous. There’s the chance that Atsumu’s heat will trigger his rut, which he wishes it would and would not at the same time. 

Fucking Atsumu in heat is an entirely new experience Suna soon finds out, mind drunk on omega pheromones. It’s even hotter, even wetter and Atsumu cannot stop himself from moaning and begging. Suna wants this to last forever. He’s lost count on how many times he’s come, lost count of how many times Atsumu has come. Their days consist of eating, fucking, sleeping and fucking again. 

He has been close to biting a few times, especially when Atsumu had been desperate for it. Suna doesn’t know if it’s the heat talking or if it’s something Atsumu truly wants, so he doesn’t, tries to keep his fangs hidden behind his lips. 

It’s torture of the sweetest kind and his mind is running wild with want.
“Fuck Atsumu, so good, so fucking good,” he moans, teeth scraping dangerously over Atsumu’s scent gland. The omega bares his neck, whimpering when he feels Suna’s fangs nibbling on it. 

“Mate me,” he begs. “Mate me alpha, please.” 

“Gonna mate you,” Suna promises, voice rough in Atsumu’s ears. “Mate you and breed you, stuff you until you’re heavy with my pups.” 

Atsumu comes with a long whine then, hole clenching and fluttering as Suna’s knot catches. He comes hard, body shaking as he spills into Atsumu. They lie together for a while as Atsumu’s wave slowly fades, Suna’s arms wrapped around the omega. When he slips out of him, Atsumu suddenly turns.

“Why didn’t you mate me,” Atsumu asks, voice clearer than it has been the past few days. “Am I not good enough for ya? Do I not smell good, am I not beautiful enough, do you not like fucking me enough?” It sounds like he’s close to crying, sniffling his nose as he tries to curl into himself. “I thought – I thought you wanted me as your omega,” he continues when Suna doesn’t respond. 

“Shit Atsumu,” he whispers, pulling the omega closer. “Are you serious? Do you mean it.” Atsumu stills, wiping his eyes as he tries to bury his face further into Suna’s chest. 
“I thought that was the entire point. Sure, I wanted to be an omega, but I wanted to be your omega. Always have. So when you suggested helping me I thought – I didn’t think it’d be like this.” 

“I fucked that one up, huh,” Suna says after a moment. “I’m sorry, so sorry. Of course I want you as my mate, of course I want you as my omega. You’re so perfect, so amazing.” He runs a hand through his hair and takes in a shaky breath. “I probably should have said something earlier, way earlier. But I’ve loved you for years now. I never thought we could be together, because I thought you wanted an omega and not me. But I’ve always wanted you, regardless of your gender.” 

Atsumu really is crying now, shoulders shaking lightly.
“Promise you’ll mate me when the next wave hits,” he murmurs when his crying stops. “I want to be your mate, want to be your omega.” Suna’s heart clenches. “Want to have your pups,” Atsumu whispers and Suna growls softly. 

“I’ll mate you next wave, I promise. And then I’ll breed you, like a good alpha. Because you are my omega, only mine and I’ll give you healthy pups. You’d be such a good mother to them, wouldn’t you.” He can feel Atsumu’s body run hot again, can smell the pheromones clouding his senses again. 

“Yes, yes I’d give you good pups, pretty pups,” Atsumu babbles as he grinds against Suna’s hips, body pleading the alpha to take him. 

“Present for me then, omega. Show your alpha that you’ll be good.” Atsumu scrambles to obey and Suna almost laughs at the contrast between this and all those months ago when they first started their adventure. 

“Good boy,” he praises, running a hand up Atsumu’s spine as he mounts him. “Still so tight, even after all that fucking we did,” Suna groans as he slides back into the omega’s warmth. He picks up a steady and harsh pace immediately, body aflame with need now that he knows Atsumu wants to mate. His hand snakes around Atsumu’s side, taking his cock into his hand and pumping it in time with Suna’s thrusts. 

“Close, so close alpha,” Atsumu moans and he bares his neck, preparing for Suna to bite him. The sight makes the alpha growl, folding over further until his teeth are grazing over the omega’s bruised skin. He bites down hard when he comes, filling the omega, letting him milk his knot. Atsumu goes boneless in Suna’s hold when he comes, knot and mating bite almost too much pleasure for him.

Suna licks at the wound gently, waiting for the omega to slowly come to again. It feels unreal, the steady thrum he feels now that they are mated and it takes a moment for him to collect himself. 

“I love you,” he whispers when Atsumu looks at him. “Always have, always will.” 

He looks good like this, fucked out in their nest sporting Suna’s mating bite. Like Atsumu was always meant to be here. Suna knows he will never tire of this sight. He presses a gentle kiss to Atsumu’s lips, just because he can. He’s his now, after all.

“I love you too,” Atsumu whispers back once they break apart. “Always have, always will.”