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Sweat is rolling down his neck when Katsuki wakes and sighs because, fuck, this summer’s heat is killing him. Normally, he loathes the cold and relishes when the temperature starts to rise once again. But this…this is just too hot. He reluctantly rolls to plant his feet on the cool floor and rolls his neck, making it crack. He stands slowly, still a little groggy, and drags his feet over to the air conditioning unit to click the power button. Generally, he tries not to use it because of energy conservation and a healthy respect for his electrical bill, but as the blessedly cool air blasts over his sweat-slicked skin, he breathes a sigh of relief.
“Kachaan, come back to bed,” a deeply familiar voice calls to him gruffly and Katsuki startles a bit, and hazy confusion clouds his mind.
“Deku?”
The thin sheet on his bed is tossed back and Izuku is laying in Katsuki’s bed, dressed only in his boxers. He pats the empty spot next to him in invitation.
Katsuki has seen the nerd naked so many times in the locker room and his eyes never fail to absorb every detail of his childhood best friend. Izuku shot up in their third year of high school, growing rapidly to the size of All Might and something in Katsuki couldn’t help the longing looks and fantasies that often terrorized his mind late at night. He’s been pining for so long, but even he can admit that he’s a coward when it comes to his hulking friend and hero partner. Can’t help wondering…
But that doesn’t explain why the nerd is here now, in his bed and beckoning him like they’re suddenly children again having a sleepover. “What are you doing here, Zuku? Thought you were on a mission?”
“Just got back,” Izuku explains in a gravelly voice, like it explains everything. “Wanted to see Kachaan.”
Katsuki steps closer to the bed and raises a dubious brow, “And you just decided to come crawl into my bed in the dead of night?”
Despite his size and now rugged appearance, Izuku still manages to blush, highlighted by his freckles that Katsuki has attempted to count on more than one occasion. “Would Kachaan like me to leave?” He asks innocently enough, but Katsuki knows him better than that…and sees the glint of challenge in Izuku’s gaze.
Katsuki thinks over his question carefully, thoughts whirring much like the air conditioner humming quietly in the room. Does he really want him to leave? Katsuki’s gut warms looking at Izuku, laying in his bed and asking for him. It’s like his fantasies coming to life. Fuck, he really wants him to stay. It’s selfish and knows that Izuku will probably always see him as a platonic friend, but Katsuki craves more, but will take whatever he can get. “Nah, nerd, you can stay,” he clips out and starts to crawl back into the bed to lay next to the object of his secret affections.
He gasps in surprise when a large and strong arm wraps around his middle and pulls him backwards until his back is flush to Izuku’s firm abdomen. A little panic erupts as his heart rate feels like it might burst through his rib cage at the proximity. He doesn’t remember Izuku ever initiating contact like this. His skin tingles wherever they touch.
Suddenly, a nose nuzzles the back of his hair. “Missed you,” Izuku murmurs softly and his arm tightens a little around Katsuki’s waist. Fuck… what is this?
He likes this, a little too much, but something is weird here. “Deku, you get hit with a quirk or somethin’?” he asks suspiciously, but relaxes in the hold anyway.
Izuku hums noncommittally and his hand brushes over Katsuki’s abs. The dark of the room hides the blush that rampages over Katsuki’s features, and he’s thankful that he’s facing away from the nerd and his ever perceptive emerald eyes. “Nope,” Izuku finally answers quietly as his hand roams upward over Katsuki’s abdomen and a calloused thumb circles one of Katsuki’s sensitive nipples. “Just needed to feel you against me.”
A shiver passes through Katsuki that has nothing to do with the rapidly cooling air blowing over his damp skin. He doesn’t want to ask and risk Izuku stopping, but curiosity overwhelms him. “Nerd, what are you doing? What is this?”
Izuku doesn’t answer right away, like he’s calculating his answer. Katsuki jolts and his breath gusts from him on a wheeze when his nipple is pinched between those strong questing fingers, forcing it to pebble. He arches involuntarily into the touch. The fingers slowly release and drag over his skin to his other nipple and begin stroking over the nub and pinching, showing it the same treatment. He doesn’t know what’s going on, but his cock fills and aches in his boxers with the erotic touches. His chest has always been so sensitive. The soft press of lips against the back of his neck makes his neck tilt and a groan leak between his lips. Izuku’s fingers release his nipple and grip his pec, massaging the flesh. “Tell me to stop,” Izuku whispers against the shell of his ear, before nipping gently at the flesh of his neck.
A heady mixture of confusion and unadulterated lust floods Katsuki and his cock leaks, no doubt creating an embarrassing wet spot on the front of his boxers. He should protest, get to the bottom of Izuku’s sudden interest and forwardness. He should be asking questions, but fuck, it feels so good to finally have Izuku’s hands on him. “Please, Zuku…” He mutters instead, as Izuku’s hand suddenly travels south to pet over the soft blonde hair of Katsuki’s happy trail.
“Please what, Kacchan?” He asks in a deeper tone than Katsuki thought was possible. “Please stop? Or please keep going?”
Katsuki sucks in a deep breath when Izuku presses firmly on his navel, forcing his ass backwards to press against a firm bulge that Katsuki can’t mistake for anything other than Izuku’s hard cock. He’s only ever seen Izuku’s cock soft between his legs, but even then it lays heavy and thick. How the nerd was ever blessed with that monster, Katsuki will never know, but right now it feels like an exciting and intimidating sign that Izuku desires him.
Izuku grinds forward between Katsuki’s cheeks, reminding Katsuki that the nerd asked a question. His mind is overwhelmed with images of Izuku touching him, making him beg, filling him up and all of his questions/protests fly from his head with a vengeance. “Please, don’t stop…”
Izuku groans behind him, a deep and animalistic sound that resonates against Katsuki’s skin and he tilts his hips backwards to grind against that thick cock wantonly. “Yeah? Is my Kachaan going to let me take care of him?” Izuku mutters seductively against the skin of Katsuki’s neck, still pressing firmly against Katsuki’s navel and rolling his hips to meet each one of Katsuki’s desperate movements. More liquid leaks from Katsuki’s dick and he moans.
“Fuck…Zuku,” Katsuki grits out with a needy whine.
A harsh bite against his neck makes Katsuki moan. “Sugoi, Katchaan. Always the best at everything,” Izuku whispers and his hand slides from Katsuki’s navel and dips beneath his boxers. Warm fingers grasp Katsuki’s dick firmly and drag against Katsuki’s oversensitive and flushed skin in a solid upwards stroke.
“So wet for me, Kachaan…” Izuku’s dark tone sends a shudder through Katsuki as a firm thumb circles over his tip. Katsuki can’t think, laser focused on the pleasure rippling through him. Izuku wets his palm in Katsuki’s precome and begins working his cock slowly and Katsuki’s hips settle on a rhythm of their own, alternating between thrusting into that strong grip and rocking back against Izuku’s clothed cock behind him.
It doesn’t take long for tension to start building in Katsuki’s guts and his legs start to quiver with the need to cum. He should be ashamed at how quickly his release rockets through him, every nerve in his body lighting up and warm cum shooting from his cock to cover Izuku’s hand still milking his cock with slow pulls.
“Good boy, Kachaan,” Izuku praises and kisses his neck, sucking at the skin until Katsuki’s back bows and he just knows that he’s going to admire the mark in the morning.
Izuku releases Katsuki’s spent cock, and Katsuki almost whines when his hand retreats all together. Before he can say anything though, his boxers are jerked down his thighs and slicked wet fingers slide between his cheeks, pressing against his twitching entrance. “Mmmm Kachaan is so tight. Gonna work this tiny hole open and stuff it full,” Deku mutters quickly, almost to himself. Katsuki clenches tightly around nothing and his cock gives a twitch, trying desperately to rally again.
“Fuck, Zuku, when’d you get such a dirty mouth?” Katsuki rasps out when the tip of a thick finger breaches his tight rim.
“Wanted you for so long, Kachaan,” Izuku states simply and twists his finger deeper. Katsuki’s hips jerk backwards to meet it and force it even further.
“Want you too, Zuku,” Katsuki admits breathily as another finger plunges in next to the first, stretching him with a slight burn.
“I know, baby,” Izuku purrs. “I’ve been paying attention. You’re not exactly subtle, you know. Looking at me, begging for me to fucking ruin you.”
Katsuki grunts when those scarred fingers curl inside him and drag against his clenched tunnel walls. Izuku sets a steady rhythm, pumping slick fingers deep, knuckles tapping against his ass. When a third finger is added, he impatiently ignores the light burn and begins thrusting his hips back with more force, increasing the pace and riding them hard.
“Always so impatient,” Deku chuckles and abruptly pulls his fingers out with a wet sound that makes Katsuki’s face heat. “You want it that bad, Kachaan?”
Katsuki grinds his ass back and wiggles it, trying to tempt Izuku to fill the raging emptiness infecting him. “Fuck yes,” he responds heatedly.
Izuku chuckles again, a dark sound filled with promise and Katsuki feels the anticipation race through him, knowing that he’s about to get more than he bargained for. He feels the shift in the air, almost electric, like the same sizzle he feels whenever Deku fires up his quirk.
A thick cockhead notches against his entrance. This is finally happening…fuck, so big. The urge to be full and claimed overwhelms him. “Please, Zuku,” he begs. “Need you. Please, fuck me.”
“Kacchan is so pretty when he begs,” Izuku growls and that thick head presses past Katsuki’s resisting muscles. He’ll no doubt be ashamed of the undignified squeal that fills the air as Izuku’s cock stretches him wide with unrelenting pressure. “Fuck,” the nerd exhales and presses further. “So tight for me, baby. Gonna carve out space just for me. Fill you full of my cum and make you gape. Fuck, Kachaan. So perfect for me,” he rambles and Katsuki clenches hard at the filthy words tumbling from those normally congenial lips. “That’s it, baby. Bear down. Let me in.”
Katsuki tries to relax through harsh panting breaths. Izuku’s hand wraps back around him and grips Katsuki’s cock again and starts stroking, bringing him back up to hardness in record time. His muscles relax at the intense stimulation and Izuku’s cock delves deeper inside until his hips meet Katsuki’s ass with a harsh smack. Fuck, he’s so full. Lungs working overtime, he tries to breathe through the intense pressure and heat impaling him.
“Such a good boy, taking all of me.” Izuku keeps up his steady strokes over Katsuki’s dick making him squirm in pleasure, forcing the cock inside him to twitch.
“Please….move,” Katsuki begs as his hole begins to relax and the burn abates to a pleasurable level.
Izuku pulls his hips back, dragging heavily against Katsuki’s walls. When he drives back in, Katsuki wheezes as it feels like that cock forcibly pushes the wind from his lungs. “So deep,” Katsuki gasps.
“Mmmmm,” Izuku mouths against the back of his neck, when he repeats the motion and grinds against Katsuki’s ass still stroking Katsuki’s cock.
A familiar tingling draws Katsuki’s balls up tight when Izuku switches his angle and Katsuki jolts as that thick cock presses right against his prostate. He hears Izuku chuckle again, and suddenly Katsuki is being rammed with brutal thrusts that make him cry out. Now that Izuku has found it, he ruthlessly pegs Katsuki’s spot over and over again. Fuck, he’s going to spill again and Izuku has barely even started.
Izuku’s hand on his dick speeds up to match his merciless thrusts. “F-fuck, Zuku. Gonna–”
“Cum for me again, Kacchan,” Izuku orders in a harsh voice. Pure electricity fires through Katsuki and his vision whites out as his orgasm slams into him like one of Izuku’s famous ‘Smashes.” He convulses as Izuku continues to work his cock and pummel his insides. He howls as oversensitivity starts to turn the pleasure sharp and biting.
Izuku mercifully releases his cock, but grabs his hip in a bruising grip and shifts to only graze Katsuki’s prostate with every punishing plunge. “God, Kachaan, so fucking hot when you cum,” he grunts out.
Green glowing light is the only warning Katsuki gets before he’s suddenly empty and flipped roughly to his back and his legs are pressed to his chest in a move so fast that his head spins. Izuku plunges back into his hole with a wet squelch and rails against his ass, making Katsuki scream at the change. “That’s it, Kachaan. Scream for me.”
Izuku’s eyes are the most intense that Katsuki has ever seen, staring down at him like he’s prey while green lightning arcs around Izuku’s limbs and gives the room an eerie light. Emerald eyes almost seem to glow as they pin Katsuki in place. It makes his head feel floaty when Izuku’s pace is almost too fast to see as his hips piston against Katsuki’s ass.
Before he can even process the feeling, Katsuki screeches when another orgasm rips through him, making his back arch dangerously, as thin nearly clear fluid gushes from his slit.
“So fucking good for me,” Izuku growls through clenched teeth, suddenly leaning forward over Katsuki and bracing large muscular arms on either side of Katsuki.
His breath is sucked from his lungs when lips crash against his and a tongue forces its way into his mouth. Izuku swallows his moan greedily and wraps his tongue around Katsuki’s and sucks hard. Katsuki feels lightheaded and dizzy from the assault of pleasure and Izuku’s plundering quest to conquer Katsuki’s mouth.
He heaves a lungful of air when Izuku finally releases him. Their eyes meet and Katsuki’s widen at the intensity of his childhood best friend. “You’re mine, Kachaan,” Izuku whispers harshly and drives deep into Katsuki and stills. Katsuki’s eyes clench closed as warmth suddenly floods his lower body and more fluid is forced from his own cock. His eyes flutter as pure euphoria washes through like a giant wave pulling him under, deep deep into the darkness.
***
Jerking upright with a gasp, Katsuki frantically looks around the room, disoriented and confused as his alarm clock rings persistently. He slams a palm over the top to stop the annoying sound and glances to the bed next to him, where only space and cold sheets greet him. Pure disappointment washes over him… Just a dream then. He sighs heavily and moves to get out of bed, groaning at the ache in his muscles. Maybe he needs to go a little easier on himself at the gym. He notices with a start the wet patch on the front of his boxers and grimaces. His face heats unbearably as images of the dream flash before his eyes.
Jesus, he needs to get ahold of himself. Hasn’t had a wet dream like that since high school.
He slowly pulls himself out of bed and sheds the soiled boxers, tossing them in the hamper near his bedroom door in shame and heads into the attached bathroom for a shower before patrol. Fuck, how is he supposed to face his hero partner today…
Katsuki stops dead as he passes by the full-length mirror in his bathroom and something catches his eye. He turns his neck to the side and stares…at the large purple bruise bracketed by teeth marks covering his fair skin. He reaches up hesitantly, not really believing his eyes and presses lightly against the mark, where a dull ache spreads under his skin.
He glances further down to the clear fingertip bruises covering his hips and runs his fingers delicately over them.
Oh my god…how is he going to face his hero partner today…
This can’t be real. Katsuki runs back into his bedroom, but there’s no sign that Izuku was ever here. Fuck, maybe he left…Katsuki’s heart sinks a little bit. Fuck, maybe he was just a one night thing, not even good enough for his friend to stick around. He’ll never admit to the hurt that spreads through him like a painful pervasive weed at the thought.
DING! His phone chimes pulling him out of his spiraling thoughts. He pulls it from the nightstand where it was charging overnight and glances at it with blurred watery eyes.
Deku: Sorry, baby. Had to leave early for a call to a robbery, but I’ll be back soon with breakfast and coffee. Can’t wait to see you <3
Katsuki smirks and wipes his eyes quickly. Stupid nerd. Katsuki thinks he might be in love.