Work Text:
For as long as Izuku can remember, Kacchan has made his lunch. When his parents would insist he help them in the kitchen to pack lunch for his day at primary school, he would stomp his foot until they agreed to let him bring a bento for his Deku, too.
Izuku doesn't realize it's a little strange until middle school. When Kacchan still brings him lunch— with a side of ridicule and public humiliation.
He'll throw the neatly wrapped box on his lap after shoving him down in a shadowed corner of the school.
"Here, quirkless shitnerd," he'd say, and then stomp off with a sneer.
And it was always so yummy. It wasn't as if they were themed or anything— no cute little squid-shaped sausages or omurice with a message on top. But it was all filling and so yummy that Izuku thinks Kacchan could open a bento restaurant if he ever got tired of being the Number One Hero someday.
Lately, though, it feels a little… different?
Today, he's gotten the usual bullying. A mean word or two written in ink on his locker that's easy enough to wipe away. Someone dropping a worm on his desk.
Then lunch came around and Katsuki threw the bento at him as he passed by with his group of friends— all of which left him 'friendly' pats so hard that they'll surely leave a bruise or two.
But when their rowdiness fades, and Izuku is carefully prodding at the knot of his wrapped bento, he's startled to look up and see Katsuki still there.
"Ah…? H-hi, Kacchan."
Katsuki grunts.
It's just the two of them in the classroom now. Izuku gulps a bit as he hurriedly thinks back to any time he's annoyed Kacchan over the last week— no, last month— but nothing comes to mind. There would be no reason for him to get beat up during lunch time.
He keeps his mouth shut, though, and darts his eyes away when Katsuki lifts a challenging brow.
"Gonna fuckin' eat or what, nerd?"
"Huh? Oh!"
Izuku opens the bento fully with a bow of his head. "Th-thank you, Kacchan. I… It looks yummy."
It's fried chicken today, with a side of potato salad. It's still a bit steamy after being insulated so well, and Izuku's mouth waters as the smell of it wafts up to him.
There's a sauce on the side, too, in a little container. Izuku pokes it curiously, because it doesn't really look like mayo or anything?
"Pour it on," Katsuki grunts, shoving his hands in his pocket. "Made… somethin' special, you could say."
"Oh…?" Izuku glances at it a bit more warily now, lifting the lid to his lunchbox like a shield as if the entire meal will explode.
Katsuki stomps his foot, and there's a deafening pop as he sparks his quirk. "Just try it, nerd!"
"Sorry, sorry!"
Izuku scrambles to obey, shoving the tip of his forefinger in the strange new sauce and quickly smearing it on his tongue.
The flavor hits him belatedly, not at all what he's expecting. It's… hard to describe, actually. It tastes savory, he guesses? But not like a barbecue or sweet-and-sour. Definitely not mayo, too salty.
It's almost sweet, actually. Izuku scrunches his nose up as it spreads further across his tongue. Somehow also incredibly bitter.
"What is this, Kacchan?"
Kacchan has a strange look on his face, eyes entirely focused on the finger that Izuku proceeds to lick clean as he tries to place the flavors. It doesn't look like it has any seasoning in it— just some sort of off-whiteish… cream?
"Don't worry about it," he says eventually. "Just thought I'd let you be my guinea pig."
Then he stalks off, shoulders hunched up towards his ears.
Once he gets to the door, though, he turns back with a smirk that makes Izuku wary all over again.
"Make sure you eat every bite, or I'll kick your ass. Didn't slave away making that shit for nothing, got it?"
"Yes, Kacchan!" Izuku yelps hurriedly. "It's yummy, see?"
Izuku grabs for his chopsticks and dunks a large helping of the chicken in the sauce, before shoving the entire dripping mess into his mouth. The flavor makes him shudder a bit until he gets used to it again, but the moan of pleasure as he swallows it down isn't dramatized in the slightest. Kacchan can cook.
He chews happily, almost forgetting that he's being watched until Katsuki kicks the door open and then slides it shut behind him without another word.
How… strange? Ah well. He didn't mind being Kacchan's guinea pig if he meant he kept getting yummy food like this!
Izuku curiously dips his chopsticks in the white sauce again, just to taste it again.
---
Katsuki slams his door shut as soon as he gets home, shoves his pants down just enough so that his cock can flop out, and jerks himself off so hard that it misses the wad of tissues he grabs and soaks into his carpet.
"Fuck—!"
"Language, brat!" Mitsuki yells from deeper in the house. Katsuki kicks his door, and then yells obscenities into his pillow when he realizes that his cock is still hard.
Stupid Deku, eating his cum so eagerly. His words keep echoing in Katsuki's brain: "It's yummy, it's yummy!"
It had been a spur of the moment decision. He wasn't sure what, exactly, he'd wanted to happen. He just knew he wanted to see the look on that shitty nerd's face when he tasted cum.
He didn't realize how… erotic it would be. It clung to his tongue stubbornly for a moment, when he'd slurped it off his fingertip. And he'd only blinked a little at the taste, and then went in for more.
"Slutty fucking… nerd," Katsuki pants, fisting his cock with a tight grip. He fucks into it as he envisions Deku licking his lips, cum painting him from forehead to chin as he moans out a sultry, 'Kacchan, suggoi…!'
Katsuki cums three times within the same hour that day.
---
And so, slowly, Katsuki gets Deku used to the taste of cum. Of his cum. Drizzled on food, mostly, but sometimes mixed in a sports drink under the guise of a new protein additive. He's not exactly lying, right?
And Izuku will blush a bit, his cheeks darkened with freckles growing even darker as he ducks his head and murmurs a happy, "Thanks Kacchan!" before he consumes everything Katsuki gives him.
The nerd'll probably get chubby by Christmas if he keeps this up. He'd doubled his servings, even, just so that he can watch Deku enjoy it longer.
---
It all comes to a head a couple months later. Just after winter break, Katsuki kicks his feet up on the desk as soon as they're the last ones in class and shoves a container towards Izuku. Izuku, who is sitting properly at his desk, as he 'oohs' and 'aahs' over the special cupcakes that Katsuki had made just for him.
Pink ones, with 'white frosting'.
It's goopy, spilling everywhere as Izuku lifts the treat to his mouth and takes a bite. His cheeks puff out as he trills happily, eyes squeezing shut as he hurries to like the 'icing' up before it spills and stains his uniform.
"Aah, Kacchan's special sauce is so versatile."
Katsuki freezes.
"Eh? What'd you say?"
"Kacchan's special sauce! This is the same recipe, right? It tastes so good on sweets and savory food— I don't know how Kacchan does it," Izuku praises readily. "Of course Kacchan would figure out a condiment that goes with everything. And it's so yummy every time."
As Izuku continues to gush over it, Katsuki squeezes his legs shut. His cock is getting hard, dammit. As if the nerd is praising it directly, instead of just by proxy.
Which…
Gives him an idea.
He and Izuku weren't exactly what anyone would call close. Not with how often he'd threaten the nerd with swirlies. But they've gotten a bit closer ever since Katsuki got more 'involved' making his lunch.
Katsuki's kind of curious to see how Izuku will react when he finds out what exactly that 'special sauce' is that he praises so much.
He stands up, thankful that their uniform is black. It conceals his erection when he faces Izuku head on.
"Oi. Close your eyes."
"Hm?" Izuku is just shoving the last bit of his cupcake in his mouth, cheeks ballooned out ridiculously. Katsuki wants to pinch his ugly (cute) face.
"Just do it."
Izuku chews his mouthful thoughtfully, eyes blinking up at Katsuki so innocently that they shine like pearls. Then he nods, straightens his spine, and lets his eyes flutter all the way shut.
"Don't…" Katsuki licks his lips. "Don't open up 'til I tell you. Don't want you spoiling it."
"Okay, Kacchan…" Izuku says, confused.
Katsuki pulls his cock out. It looks so lewd right next to Izuku's relaxed face, crudely dripping precum all over the remnants of old cum that sits on the plate Izuku left behind. If he inches forward, it'll press right against Izuku's freckles.
He is careful not to groan as he slowly slides his palm across the underside of his cock. He can't help his sharp inhale though— he's so fucking aroused right now that it hurts.
"Kacchan?" Izuku whispers.
"Hnngh—" Katsuki bites his tongue to shut himself up. "Shit."
Izuku nervously licks his lips again. They look so plush and soft. Would be a perfect place for his cockhead to rest. Would Izuku be the type to gently kiss at a cock before it fucks his face, or would he be so eager that he lets his mouth hang up like a whore so his partner could fuck into it however they chose?
Katsuki isn't sure which one he'd want to be true more.
He ever-so-slowly glides his hand from tip to base. It's so hard to keep it from making that slick sound as more of his pre builds up and coats his palm. But he can't resist the orgasmic slide as that friction finally gives to something smooth and hot.
Izuku awkwardly shifts in his seat, and Katsuki plants a heavy hand down on the desk. The slam of it makes Izuku stiffen again, going still like a statue so as not to invite Katsuki's ire.
Katsuki huffs a laugh, stroking himself faster. He isn't sure if the noise is loud or if he's just hyperfocusing on it in his ears, but Izuku doesn't say a word.
Izuku's slowly nibbling on his lower lip. He'll make it swollen and chapped if he keeps that up.
Katsuki's hips jerk forward of their own volition as Katsuki's head tilts back, hissing his moan out through clenched teeth.
"Ah, fuck. I need— fuckin'… scooch back a little."
Izuku jolts as he's addressed, and his eyes begin to flutter open until Katsuki slams his palms across them.
"Eyes closed."
Izuku mumbles out a stammered apology as he leans back in his seat. The chair scrapes across the linoleum and Katsuki grunts as he sets himself atop Izuku's desk, tossing the junk atop it to another extra's desk.
Like this, his cock is pointed directly at Izuku's face. If he isn't extremely careful, or if Izuku gets too comfortable and leans forward, he'll end up with it pressed against his nose.
Katsuki is so excited that his cock bobs in the air even without him touching it. He wants to make Izuku open his mouth, so that Katsuki can aim his cock at it and have him finally swallow fresh cum from the source.
But, despite being a shitnerd, Izuku was too smart for that. He'd definitely connect the dots.
So Katsuki just has to be happy with jerking himself off while the nerd sits there and waits for it. Katsuki huffs out his nose again, just barely muffing moans, and Izuku makes a curious noise in response.
Katsuki slips his fingers from Izuku's eyes, but the other boy keeps them obediently closed. He must feel the heat of Katsuki being so close, because his hands hover awkwardly in the air until they, finally, drop atop Katsuki's upper thighs. Just to touch.
"Yeah," Katsuki grunts. He strokes his cock faster. The noise is unmistakable now, wet and rhythmic. He can't stop himself if he actually wanted to. Later, he'll try to blame it on… on a fuckin' condiment jar or something. Izuku won't have to know— he'll just drink it down from the source and love it as usual.
Katsuki moans aloud, the noise hoarse from holding himself back. He feels a shiver roll down his spine as Izuku's fingers tighten on his thigh, as if encouraging him on.
He plants his hand flat behind him to balance as he begins to fuck his own fist, forgetting himself for a moment.
Izuku gasps. Katsuki snaps his head down to look, and— oh fuck.
His cock looks huge next to Deku's face. His eyes are wide open, partially crossed as he looks at the very tip of it as it smudges wet against his forehead. His lips quiver as he tries to think of something to say, but all that succeeds in doing is getting his lips wet with precum, too.
Katsuki reacts first.
"Open your mouth," Katsuki snarls, pace faltering but picking up where it dropped off almost immediately. "You wanted more, didn't you? Got fuckin' addicted to my cum without even knowing it."
Katsuki shoves his thumb past Izuku's lips when the latter is too slow. Katsuki can feel the beginnings of his orgasm as his balls draw up, eager to paint his nerd white with his seed.
He jerks himself off a few more times, moaning freely now. Izuku's tongue pushes against the finger that rudely yanks his jaw down, but otherwise Izuku doesn't try to get away. He just has that flustered expression, eyes so focused on Katsuki's cock that he doesn't care about how lewd the rest of him looks.
Katsuki cums all over his dumb face.
Izuku lets out the softest, "Oh!" as the warmth of it spurts across his skin. His eyes squeeze shut just in time for a few thick ropes to land across there and tangle in his lashes.
Most of it lands against his lips as Katsuki angles himself down, pumping the very base of his cock so that not a single drop will be wasted. A mouthful lands across Izuku's tongue, but he can't swallow it properly with Katsuki's thumb still holding it open.
Katsuki feels the way the tip of Izuku's tongue keeps playing with it, as the events slowly catch up in Izuku's brain.
When he finally realizes that Katsuki had been jerking off to him (had fed him cum, and that he'd liked it), Izuku freezes.
His tongue is coated white with cum. He gurgles a bit as he tries to speak, but Katsuki tuts.
"Don't be rude, Deku. After I went through all the trouble of making a fresh batch for you."
Katsuki's heart is pumping so hard that he'll be feeling the effects of this adrenaline rush until he's an elder. He brings his other hand up to curl across Izuku's cheek and rub a seemingly gentle circle in the skin.
"Be good and drink it all down for me. Wouldn't wanna waste it, right?"
Izuku whimpers, but his plush lips slowly close around the appendage in his mouth. He swallows loudly, all of it at once, and it must still be warm as it goes down because he shivers and moans softly as one of his hands twitches towards his throat.
Katsuki's thumb presses against the center of Izuku's tongue as soon as it's clean, to feel the texture of it. Izuku won't look him in the eye just yet, but his fingers gently curve around Katsuki's wrist, as if to keep him there.
"There we go. Yummy, ain't it?"
"Mhm," Izuku agrees, softly. He looks like he's fucking in love, blushing as if Katsuki just confessed to him.
Katsuki watches as some of his cum begins to drip down Izuku's face, and his left eye is forced shut again as he's coated down to his chubby cheek. Katsuki lets the beaded pearls gather on his finger tip before he brings that finger, too, to Izuku's lips.
Izuku drinks it down like it's the nectar of gods— and fuck if that isn't a turn-on.
Katsuki feeds Izuku another fingerful, letting it smear messily across his lips and his teeth until Izuku huffs and opens his mouth wider, so that Katsuki knows exactly where to aim.
Katsuki's dick gives a valiant twitch.
Eventually, he lets Deku go. He pulls back with a satisfied huff, unashamed of the way his cock has flopped, softened, against his lower belly.
"Damn. Shoulda been letting you suck me off every day instead of feeding it to you in those stupid bentos, huh?"
Katsuki lets out an ugly snort, just as Izuku perks up.
"Oh!" Izuku lets out an excited gasp, hurriedly rubbing a dollop of cum from his eye with his sleeve. Katsuki grunts as Izuku shoves himself away to grab for his bag, fingers digging painfully into his thigh.
"Fuckin' ow—"
"Here, Kacchan!"
A small present is deposited in his hands, where he'd been reaching forward to pinch Izuku as a punishment. He blinks down at it stupidly, as if it were a two-headed pixie.
But no. It's just a box. No bigger than his palm. He hefts the weight of it, but it's light. There's something the shifts inside of it though, so Katsuki lifts his brow.
"Happy Valentine's Day," Izuku murmurs shyly. He hides his coy smile behind his hand, ducking his head down as he blushes like a virgin. Like Katsuki didn't just cum all over him.
Katsuki opens the present.
An All Might figure. A small one, but high quality. Katsuki can tell by the gold foil that decorates All Might's signature hairstyle.
"What the fuck."
"It's to thank you for always making me lunch!" Izuku preens. "Kacchan was always so kind, so…"
Izuku gestures to the figure emphatically. He wipes more cum away from his cheeks, and absently licks a drop from his fingertips. He really does love the taste so much. Katsuki wants to fuck his mouth again, and see just how good at swallowing they can train him to be.
There's a brief moment of silence. Then,
"Ah, Kacchan? Why are you hard again?"
Katsuki buries his flustered face in his palm. His other drops his gift so that it can wrap around his cock once more. "Just… shut up and close your eyes again, nerd."