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Katsuki thought he’d won the jackpot. Really.
Having reached the ripe age of thirty-nine (which is not that old, fuck you very much, Kiri) he didn’t think life could still be so surprising. Especially since his days were so carefully arranged by his PR team who, for some reason, still wanted him to attend public events and do those dumb photoshoots. You’d think that after fifteen consecutive years of systematically being awarded the Number One title that shit would stop.
And then that fateful mission came.
Katsuki found himself stuck at Mirko’s agency for two long weeks, working on a difficult case, and he was not expecting the most taxing task to be learning how to coexist with a perpetual hard-on, holy fuck. When the rabbit hero had told him over the phone ‘bring your sidekick and I’ll bring mine, we’ll make it a playdate’ he hadn’t imagined this, hell no.
But when said sidekick finally made an appearance, Katsuki almost fell out of his fucking chair.
21-year-old Midoriya Izuku was a sight for sore eyes with his skintight costume and floppy bunny ears, a smile so sweet you could taste it on your tongue, and these beautiful freckles scattered on his cheeks. Heads turned wherever he went. Embarrassingly enough, Katsuki’s head had consistently turned too, whenever the green-haired beauty walked into the room.
And then the bun proved himself to be a crucial element to the investigation, hella smart, fierce, and strong, way more than the average youngsters that haunted hero agencies, and Katsuki realized he might be a little in love.
He wasn’t planning on acting on it, okay? Izuku was almost half his age. Not to mention that the bunny had referred to him as his role model more than once.
How they ended up fucking inside one of the shower stalls of the agency at three in the morning, Katsuki still had no idea. One moment he was scrubbing his eyes, trying to get black paint off, and the next he was staring at an ungodly amount of ass, and—oh, Izuku was staring too.
That it wouldn’t be a one-time thing, Katsuki knew the moment his dick got a taste of that sweet, dripping hole.
* * *
Something’s wrong with Izuku.
It has been a few days since Katsuki noticed, actually, but every time he asks he gets the same two answers: ‘don’t worry about it,’ and ‘I’m fine, Kacchan’. He’s not stupid enough to believe the words, but he doesn’t wanna overstep any boundaries by pressuring Izuku to tell him.
Still, the rabbit has been antsy the whole week.
Not that he’s normally the most collected person, but the amount of fidgeting is getting ridiculous. He twitches in his sleep, can’t seem to stay still for more than a few minutes when they’re on the couch together, and Katsuki is seriously going to lose his fucking mind if he has to endure the strenuous thumping of Izuku’s paws on the floor for one more minute. He’s trying to work, for fuck’s sake.
And oh, yeah, they fuck a lot. Like, way more than usual, and that’s a whole different suitcase to unpack because they’ve always fucked like rabbits ( ha ) but the situation is turning pathological. His dick is going to fall off if they keep this shit up.
They’ve been living together for about six months now, and Katsuki has never seen him like this. Nervous? Sure. Worried for absolutely no reason? Every goddamn day. Horny and willing to fuck ten times in the span of 24 hours? He’s twenty-one, of course he is.
But this? He has a feeling that this constant restlessness might stem from something different, and the fact that Izuku completely refuses to talk about it only makes him more apprehensive.
And then, one day, Katsuki comes home early and is presented with a scene that would’ve made his sixteen-year-old self cream his goddamn pants.
Izuku’s lying butt naked on the couch, face stuck into one of Katsuki’s sweaters and hips vigorously humping Katsuki’s bed pillow. The one he sleeps on.
He slams the front door closed, and the bun squeaks like a dog toy.
“Jesus fucking Christ.”
“K-Ka—”
“No, shut up.” He sighs, trying to keep his calm because it’s clear that Izuku won’t. “Can we please talk? I’m not going to get mad. But I need to understand what the hell is going on, or I’m gonna lose my fucking mind.”
Izuku frowns and looks like he wants to run and lock himself in their bedroom (something he’s done more than once, in the past). Katsuki throws him a pair of sweatpants he found on the floor and waits for him to quietly get dressed, then sits down next to him on the couch.
Izuku looks unwilling, but he doesn’t move from his spot. Their legs briefly brush.
There are six whole seconds of uncomfortable silence before Katsuki blurts out, “So? What’s wrong with you?”
And Izuku’s face turns completely red in shame.
“Oh, for fuck’s sake, will you just-”
“It’s a bunny thing!”
“A what? ”
“A—A bunny thing. A hare thing, really.” He looks at his feet the whole time, and pulls at his lower lip with his teeth whenever he’s not talking. “It’s just… it’s spring, Kacchan.”
Katsuki frowns. “I’m aware.”
“And it’s affecting me more than usual, I think it’s because I live with you now.”
“Wait, what? ”
“It never lasts long, it’ll be over in a week or two, I promise!”
“Izuku—”
“I’m sorry, I can stay at my mom’s house until I’m feeling better! I know I’ve been a mess, and you shouldn’t have to deal with this crap too, so I can just—”
“Izuku. Are you in heat?!”
“What? No! I mean, ugh .” He hides his face in his hands for a moment, and Katsuki swears he’s about to have a stroke. This is not where he imagined this conversation going. “I’m a male hare, Kacchan. Uhm,” he tries to smile but it looks terribly apologetic, “Mirko calls it the ‘pull of the seasons’?”
The what now?
“Oh my fucking god.”
“I’m sorry!”
“Don’t.” Katsuki sighs, trying to process all this new information he wished he knew before inviting the green-haired menace to live with him. Not that it would have changed things, fuck no, but… “I just. You should’ve told me.”
“It’s usually not this bad.”
“Still.”
“I know.”
There are times in which the gap between their ages feels a lot more prominent, and this is one of them; Izuku is smart, emotionally intelligent, and Katsuki tends to forget just how young the bunny is, and how insecure he can get about himself and the things he wants.
It’s Katsuki’s job to reassure him, to turn this relationship into a safe haven for both of them.
“How do we fix it?”
Izuku’s eyes widen. “You don’t have to—”
“I wanna,” he quickly interrupts. “I’m worried about you, and I want to help. So tell me what I can do.”
The green-haired boy looks conflicted. Like he wants that too, but is scared to ask. “Promise you won’t get mad?”
* * *
Katsuki stares at himself in the foggy bathroom mirror. His skin is still warm from the shower, and the small amount of lube spread on his fingers feels cold as hell.
Honestly, this wouldn’t be such a big deal if he had let someone else do this to him at least once. He isn’t even sure why he hasn’t.
The first lube-slicked finger sinks in easily. Katsuki wriggles it around until he’s sure he can fit another one—and it’s odd because, despite having done it hundreds of times to other people, he can count on one hand the times he’s done it to himself.
It doesn’t matter. He knows how to do this.
The second finger meets some resistance. Katsuki breathes through the slight discomfort and tries to relax. He knows he should probably give himself more time to adjust, but he swears he can feel Izuku’s concern seep from under the door, and he doesn’t want the bunny to think he’s changing his mind.
When he steps out of the bathroom, a towel firmly wrapped around his hips and lube in his right hand, Katsuki isn’t worried in the slightest. He’s… curious, actually, and maybe a bit nervous, but not worried. Somewhere between urging a third finger in and feeling his leg muscles ache from the stretch of the position, he realized he actually trusts Izuku with this.
Izuku, who’s waiting for him on the edge of the bed, pale-faced and visibly sweating. Who gets up immediately after Katsuki steps into the room, and cradles his face in his hands with care and concern.
An inhale. “Katsuki—”
“I haven’t changed my mind.”
“But—”
“I haven’t.” He licks his lower lip, then lets the small towel fall to the floor. “Let me do this for you.” Katsuki’s fingers slip beneath the elastic of Izuku’s sweatpants. “Besides, it’s not like I haven’t thought about this before.”
He hears Izuku’s breath falter. “Really?”
Katsuki almost laughs. With the sweatpants finally out of the way, he can watch his dick fill out in real time. “What? You’re telling me you haven’t?”
When he reaches for Izuku’s cock and finds it rock hard, he gives it a long, lazy pump and watches it dribble hot precum all over the side of his hand. A small breath leaves Izuku’s lips before he speaks. “Of course, I thought about it. I just didn’t think you’d want to.”
“Dumb bunny.”
When he finally gets on the bed, careful fingertips quietly trace the rim of his hole, gathering some of the lube that’s still spilling out.
“I could’ve done it for you.”
“I know.”
Izuku buries his face between Katsuki’s shoulder blades with a sob.
Fuck, it’s like he can’t help himself as he grinds down on Katsuki’s ass, hard dick sliding easily between his cheeks but never catching. And when the frantic humping doesn’t stop, the older man has to reach back and guide it, lube-slicked hand placing the mushroom tip where it’s supposed to go. It feels hot as it kisses Katsuki’s rim. Once there, all it takes is a sloppy thrust for it to slip inside.
It doesn’t hurt.
“Oh.”
One more thrust, and the stretch becomes uncomfortable. But that’s okay. He bites his lip and waits for Izuku to be all the way in.
“Doing good, bunny,” he says, and Izuku’s hips immediately stutter against his. Katsuki grins.
The minute thrusts eventually turn into something more. More powerful, more fervent. Katsuki would love to focus on them, focus on the slow drag of his boyfriend’s cock pulling out of him and quickly being shoved back in, but Izuku needs him to be present: his arms are tight around Katsuki’s waist, tense; his hips keep jerking forward without setting a real pace.
“Let go,” he finds himself saying, without really thinking about it, “I’m not gonna break. Let go.”
And maybe the reassurance actually worked, or maybe Izuku’s restraint crumbled on its own—but Katsuki is suddenly really fucking aware that he’s dating a rabbit. Holy fuck.
The thrusts are shallow, yes, but so fucking fast they’re making him dizzy. It’s not even funny, Katsuki has to hold on to the headboard like it’s a goddamn lifeline as Izuku sinks into him again and again, muffling his moans against the skin of his back.
But the spurt is short-lived, and the bunny shoots his load with a loud cry after twenty short, hectic seconds. Katsuki feels him convulse and break with overwhelming clarity.
“Sorry, ‘m sorry,” he says, sounding apologetic and mildly out of breath. “Didn’t mean to. Not this fast.”
But his dick is still hard, and he never really stopped fucking into the older man.
“It’s okay.” Katsuki tells him, “I know you wanna go again. C’mon.”
Turns out Izuku’s thighs are good for more than just riding. Getting used to the speed is a challenge: he fucks like he’s humping a goddamn pillow, like sometimes he’s too far gone to even notice Katsuki’s laying under him, taking the brunt of his mindless thrusts. It’s okay though, Katsuki’s dick is undoubtedly hard and dripping pre like a leaky sink.
When Izuku’s cock slips out after his second orgasm, Katsuki gently guides it back in so he can keep going.
They lay on their sides this time, back to chest, Izuku’s arm wrapped tight around Katsuki’s shoulders so he can pull him down on his cock with more force. Katsuki exhales harshly every time Izuku’s sloppy dick manages to hit his prostate, unconsciously encouraging the bunny to do it again and again.
By the time his first orgasm hits, Katsuki realizes he should’ve tried to hold it off a little longer. Now, as he quietly milks his softening dick and Izuku shows no signs of stopping or slowing down, he understands he might have made a mistake.
It doesn’t matter. He can keep going.
They’re both sweaty by now, but Izuku feels like a furnace behind him. Katsuki reaches back to pull his tail—gently, just a tug, something he usually likes in bed—and the gesture earns him a sharp bite on the back of his neck. Unrelenting, he grabs it by the fluffy base and pulls harder. It makes Izuku jerk back with a hiss, cock slipping out as he cums all over Katsuki’s lower back.
The bunny starts crying almost immediately after that. Katsuki thinks there must be something deeply wrong with his head, because hearing those wet sobs while he still feels Izuku’s hard dick looking for friction between his soiled thighs turns him on so fucking much. He doesn’t even care.
“Good bunny,” he murmurs, gracelessly petting the few places he can reach: Izuku’s face, the side of his leg, his stuttering hips. “Feeling better yet?”
The answer comes in the form of a whimper and a shy thrust.
The way the bun desperately keeps trying to burrow his barely hard shaft inside Katsuki’s fucked out hole would be almost sweet, if Katsuki wasn’t currently so oversensitive; he tries to guide it between his thighs instead, but it’s not good enough. Not nearly enough—Izuku makes it clear by crying against his back, by mindlessly using his hands to part Katsuki’s cheeks and make room for himself.
Eventually, he has to let the bunny push into him again.
By the time Katsuki feels ready to come again, he’s sprawled on his back and watching with absolute amazement the perpetually changing expressions distorting Izuku’s face. He watches his eyes as they go from loving and sweet to deranged in the span of seconds, his lips as they twist in an uncharacteristic smirk and—oh, fuck him, Katsuki is ready to blow his goddamn load.
And he does. White and hot, all over his own stomach. Izuku jackhammers into him until there’s not even a drop of cum left in his balls.
Izuku buries himself deep in one, two, three long thrusts, and comes with a broken sob.
This time, when his cock slides out, it falls limp and tender in the mess between Katsuki’s legs.
They’re both tired and fucked out, but Izuku looks positively drained as he lets his breath even out in the crook of Katsuki’s neck. Katsuki’s sure he doesn’t mean to fall asleep there, not when they’re both sticky with old sweat and dried cum, but when his eyes slip shut he doesn’t move to wake him.
It’s fine. He can deal with feeling gross for a while.