Archive of Our Own

No one had ever touched him there before.

With the noise, Katsuki gets more confident with his touch. 

He shoves his Izuku down flat against the concrete and shoves his hand up under his uniform so that he can pinch and twist at his nipples. Izuku gasps and writhes, fingers shaking as he unlatching the bottom few buttons so that they don't tear off.

"K-Kacchan—!" Izuku yelps. 

Katsuki shoves his palm against Izuku's face. "Shut up."

He sits up, and knocks against the metal building behind him again. Basically an oversized trailer, because the school was over-populated and they didn't have enough classrooms for all the idiots in them.

The thing provided perfect cover from all the windows, though, and who was Katsuki to refuse an opportunity like that? Especially when Izuku blinked at him with bleary eyes and a half-open mouth, eager if not shy.

"Slut," Katsuki laughs. "Open your legs."

"We can't do it here, l-like this..."

Even as he argues, Izuku slowly parts his legs and lets Katsuki take up space between them, shuddering when his hand comes back to shove beneath his trousers.

Katsuki only rolls his eyes and presses their faces together, forehead to forehead. Like this, he has an easy view of both Izuku's face and the way his cock was hard and wanting in his boxers.

Ever so impatient, Katsuki shoves the pants down as far as he can get in the position (which, not far), and pulls Izuku's dick out.

Katsuki surveys it casually. It's not small, not large. Kinda cute, for a dick.

When Katsuki rubs his thumb across it, the foreskin rolls down easy and exposes the pink, leaking tip. It's shiny with the pre, and Katsuki lets it spread across his palm before he starts jerking Izuku off with a slow, inexperienced pace.

He twists his wrist, cause that's what feels good when he masturbates, and watches raptly as Izuku's head falls back and his chest vibrates with his low moan.

He only kisses Izuku to shut him up, but the sensation feels nice enough that he keeps it up as he feels Izuku's hips jolt up towards the pleasure.

Katsuki gets a bit of a high off of that. He was making Izuku feel pleasure like that, making him moan like a whore right outside of their school— right in public!

He strokes faster, and Izuku whimpers against his lips.

"Kacchan!" Izuku hisses, teeth baring. 

Katsuki nips at his bottom lip and licks across it just because he can. "Lift up."

He lets go, rubbing the precum staining his fingers into Izuku's pants, right where it curves against his hips. Izuku huffs, but he shuts up when Katsuki glares at him.

Obediently, he lifts his hips and only shakily sighs when Katsuki tugs his pants down lower. His ass gets exposed to the afternoon sunlight, and Katsuki flips him over to spread the cheeks apart and get a clear view.

Izuku squeezes his thighs together, shocked, but buries his face in his crossed arms as he lets Katsuki do what he wishes.

Katsuki plucks a small packet of lube from his pocket. A sample size he'd snagged from the mall once.

He rips it open with his teeth and lets it drizzle across his clean hand, sticking his tongue out in disgust as he tastes a bit of it. Definitely not the flavored kind.

When he prods his middle finger against Izuku's hole, the latter's head shoots up as he moans straight into the open.

"Dumbass." Katsuki snickers, cruelly. "Open up for me, useless Deku. You're lucky I'm prepping you at all."

Izuku whines, stammering beneath his breath.

He shuts up when Katsuki presses in deeper and rubs the pad of his finger against his inner walls. Katsuki can see how red his face has gone, even as he hides it against his sleeves again.

Slowly, Katsuki prods around his entrance until it starts to loosen and let him in easy. He does it again when he adds another finger, then another, and then watches as Izuku's hole stays slightly open, twitching, as it waits for more.

Katsuki swallows heavily at the sight, especially when Izuku glances back at him. Heavy tears dot his eyelashes, the fucking crybaby, and he'd never looked so erotic in his life.

Katsuki shuffles forward, shoving his trousers down. His dick is already beyond hard, soaking into his briefs, and he only wastes a few seconds coating it with more lube before he presses it to Izuku's ass. 

"Wait! W-wait, slow— please go slow Kacchan!" Izuku panics immediately.

Katsuki steadies him with a heavy hold to his hips, soft under the tight grip, and prods at the open hole.

"Your slutty little hole wants it, Deku." Katsuki hums, pressing just the very tip in and watching how easily the entrance parts for him. Izuku reaches back, squeezing his fingers against Katsuki's wrist, and cries out when Katsuki goes in a few inches deeper.

Katsuki pulls back, until Izuku relaxes a bit and spreads his legs. Then, he plunges back in, deeper. 

"I'm just doing what your body asks," he says, easy, as Izuku cries out again, high-pitched and nervous.

Katsuki slowly rocks his cock in and out of his tight, wet ass and lets a rumbling groan release through clenched teeth. "Fuuuck."

It was a good thing they were skipping to do this, or else they'd be caught already with how fucking LOUD the nerd was being. Every time Katsuki sawed in, his insides would clamp down tight and he would squeal and shudder.

His dick was dripping steadily between his legs, though. Katsuki bends over to feel at the hard length, strokes awkward from the position.

When he finally gets all his cock inside, Izuku's upper body sinks flat against the concrete. He spreads his thighs, looking wide-eyed between their legs, and Katsuki takes the invitation for what it is.

He thrusts in hard, and their exposed skin slaps noisily together as he picks up the pace from there.

With every thrust, they grunt and moan together. Katsuki bites his lip to keep quiet, watching as Izuku falls apart with the steady fucking. 

His hole goes pliant, finally accepting the full girth of him, and Katsuki throws his head back with a groan as Izuku starts to rock with him, meeting his thrusts with his soft ass.

Katsuki palms the cheeks, pulling them apart to watch as his dick disappears over and over inside the tiny hole, stretched thin.

He decides right then that this ass was for him and him alone.

Katsuki leans down to grab Izuku by the hair and tug him back up. "Look at me, shitty Deku."

Izuku hisses at the dull pain, but is obedient as he looks at Katsuki's face. His moans sound more ragged with the new position, and he has to shove his hands flat to keep up the steady rhythm.

Before he has even decided what he wants to do with Izuku, the little nerd stutters out a soft, "It f-feels good, Kacchan."

Katsuki jolts, pressing in balls deep, and kisses him again. He bites down too hard, making Izuku yelp, and his tongue goes in too far, but they both like the rough kiss. Katsuki can tell by the way Izuku tightens down on him again.

Izuku shoves his hands between his legs and begins stroking himself off in time with the thrusts, hips rocking with every stuttered thrust.

"Shit, I'm gonna— cum!" Katsuki shoves his face against the curve of Izuku's shoulder and muffles his cries into the fabric of his blazer. "Fuck, fuck, FUCK—"

"Kacchan!" Izuku shouts with him, clamping down deliciously tight on Katsuki's dick.

One more thrust, and he's cumming deep inside. He'd meant to pull out, but fuuuuck it felt so good.

He stays balls deep as Izuku all but milks him with his ass, writhing beneath him as his own cum shoots onto the ground and stains the grey concrete. 

His orgasm is so intense that he doesn't hear the footsteps until someone lets out a sharp gasp.

In response to the noise, Izuku screams and shoves back, tumbling over. Katsuki goes with him, knees weak from his orgasm, and they both blink blearily at the sight of their principal quickly covering her face and turning away.

Shit. 

--- 

Apparently, even though the trailer was a window blindspot, it was not a camera blindspot.

They were lucky, though, that the principal had only seen them sneak around the corner and not the entirety of their fucking.

They end up with a few weeks detention, a quick sex-ed lesson from the principal and the nurse (that's more humiliating than anything), and a threat to tell their parents if they do it again.

Which, was fine with Katsuki. He'd just be more careful next time. Not that he'd tell Deku that.

"Kacchan..." Izuku mumbles, hand hovering towards Katsuki's wrist as if he wants to touch. They're on the train home, sent early, and it's all but empty.

Katsuki tch's and leans back heavy in his seat, legs spread so much that Izuku is almost a full seat away.

"What, nerd?"

He squirms, face red, and then tentatively reaches for Katsuki's hand. When the latter doesn't shove him away, he presses it against his crotch and lets Katsuki feel how hard he is.

Almost more than before, Katsuki thinks, flabbergasted.

"I can... feel it leaking out," Izuku says, nearly caving in on himself with how embarrassed he is. He sinks down low and crosses his legs at the knee.

Katsuki swears he can hear the cum squelch, spilling out of Izuku's ass and into his underwear and holy fuck.

He growls and tugs Izuku close, shoving his briefcase over Izuku's legs to hide his fingers as they dip below the waistband of his pants again.

Yeah, no way was he letting anyone else get Izuku like this.

Maybe his innocent little Deku was more of a slut than he thought.