Written by:
surveycorpsjean
Summary:
"This is where we sleep?" Izuku runs his hand over the bedspread.
Katsuki short-circuits. He hadnʼt expected—he isnʼt against sharing a bed with Izuku. But heʼd prepared another bedroom for him on the other side of the house. Just to make him comfortable and shit. He had a whole plan. But—
"Yeah," Katsuki nods. "We sleep here."
or: Izuku asks Katsuki to teach him how humans kiss...and other things.
____________________________
Izuku sprints before he can walk, right into Katsukiʼs arms as the last of his scales fade into freckled skin on his brand new legs.
Heʼs breathless.
"Kacchan. Kacchan—I did it, did you see it? Iʼve got legs. Iʼve got real legs. With feet and everything?"
"I see ʼem."
Theyʼre beautiful. Heʼs beautiful. Just as he was with that stupid-looking tail, those damn big fins.
"So...can we human kiss now? You, um...you said we would."
What a dork. Heʼs not even wearing pants and he wants kisses.
"Later," Katsuki says, as he lets Izuku nuzzle into his neck—where his gills would be if he had any—itʼs a merpeople greeting, and Izukuʼs nothing if not full of enthusiasm. "Clothes first."
"I donʼt think I need any. Iʼm good."
"Yeah," Katsuki peeks over and looks at his freckled butt, unreasonably cute. "You—you definitely do."
No one else should be seeing that. He wraps his beach towel around Izukuʼs midsection protectively as he listens to him babble, answering when he thinks itʼs necessary.
"Youʼll get your kiss. Quit naggin'."
"Yeah, I still like you."
"Of course I have food."
Somehow he manages to take Izuku up to the house without causing a major scene. Though the entire way up the beach Izuku isnʼt looking at the sand and the trees and the rocks and all the new land stuff he hasnʼt seen before. He keeps looking at Katsuki.
At the house Katsuki grabs him a loose pair of pants and a cropped shirt that matches his eyes—that deep ocean green. Izuku trips over his own feet, probably because heʼs not used to having any, but also because the pants are long on him.
So Katsuki rolls them up a bit, feeling weirdly vulnerable as he gets down on his knees.
Itʼs Izukuʼs first day on the land—why the fuck does it feel like itʼs Katsukiʼs? He's been here his entire life. It shouldn't feel new. This house. This room. Everywhere the light touches and Izuku pokes around. Like he's having the time of his life and he hasn't just left the only home he's ever known. All of his friends.
Katsuki would have joined him underwater if that was something he knew how to do. He just...didn't. He's human with obvious human limitations and somehow Izuku still thinks that everything he does is so great.
What's his problem?
"Are you okay, Kacchan?"
"Fine."
Why wouldnʼt he be okay? Heʼs not giving anything up.
The transformation, from what Katsukiʼs been told, is permanent. Izukuʼs never gonna be a fish man again. He did all this because he wanted to be here. With his Kacchan. The weight of that—the responsibility—sinks in every second.
Izuku loves home. He loves the things that he loves so much. He's obsessive and scarily observant and he's so weird. He's putting his ear up to the walls and the floor, picking up the fruits in Katsuki's fruit bowl and giving them a tentative lick, and smelling the throw pillows.
"You wanted a human kiss, right?"
"Right," Izuku says. "But not just with anyone. That wouldnʼt work. I want your kiss. You know, with you. That's...that's basically what I came here for."
Heʼs ridiculous.
One kiss and one person cannot be worth trading the whole ocean for. Especially when that person is Katsuki. What a poor fucking judgement call. What was he thinking? Who does he think he is? How dare he, actually...who does that? What the actual fuck.
Plus...it does sorta mean the pressureʼs on now to make this good. Now that Izuku is his to take care of.
Katsuki met with and promised this idiot's mom. He said he would take care of Izuku forever. He was gonna do that anyway, but it was important and stuff, to say it out loud.
"Come on," Katsuki drags him by the arm.
Into a small bedroom with the curtains already drawn. Thereʼs a bunch of little artifacts on display on his dresser: all the presents Izuku collected from the ocean floor and gifted to him. A human comb, broken mirror shards, and something Izuku thought was a big prize at the time—a whole cash register.
Katsuki doesn't even work in retail. He doesn't know why he kept the damn thing, it's waterlogged and rusted, probably doesn't even work. Just a buncha junk.
"You kept them," Izuku beams. "But you said they were all garbage?"
"They are," Katsuki says.
Of course it's trash. But...the way Izuku looked when he offered each of them up, that was...totally lame. His big, big eyes. The way he looked that first day when he pulled Katsuki up from under the water—saving his stupid life. Then doing it again, and again, and—
What's wrong with him?
"This is where we sleep?" Izuku runs his hand over the bedspread.
Katsuki short-circuits. He hadnʼt expected—he isnʼt against sharing a bed with Izuku. But heʼd prepared another bedroom for him on the other side of the house. Just to make him comfortable and shit. He had a whole plan. But—
"Yeah," Katsuki nods. "We sleep here."
Izuku lets out a noise. A faint vibrating noise like a purring cat. Katsuki thinks it means happy, he definitely hopes it does. He has no idea what he's supposed to do if that noise means pain or something.
He still hasn't thought about what he's going to do for all the regular life things Izuku's going to have to do now, like getting an ID card and a birth certificate and seeing an actual doctor.
Izuku comes over and puts his hands on Katsukiʼs neck. One of these days he's gonna have to learn that the neck isnʼt super important for humans or anything special or—
Shit.
Shit. Shit. Shit fucking—
Izuku puts his mouth there. He mouths over where Katsukiʼs gills should be then he grazes his teeth over it. And it does feel—it's...
Katsuki moans out loud and the purring gets even louder.
"Human kiss now?" Izuku touches his fingertips to Katsukiʼs mouth. "Here, right? I asked around."
Katsukiʼs head is too empty to do anything but nod. Izuku nearly bonks his head into Katsukiʼs and then nips his bottom lip with his teeth.
"No..." Katsuki laughs, shaking his head. "Sʼnot a bite. Just..."
He holds onto Izukuʼs jaw, brings their faces together before taking in the feeling of Izukuʼs soft lips. He tries to move them, still tryna talk...but Katsuki shushes him with his mouth. And when theyʼre really, properly kissing the vibrating sound crescendos until Katsuki can even feel it against his ribcage. So loud.
"I think I like this better," Izuku decides. "Better than a sea kiss."
Katsuki doesnʼt ask him if the kiss was worth it.
He knows Izuku cried leaving his home behind. Because he cries about everything. But Katsuki also knows heʼs going to do everything he can to find a way for Izuku to go back someday and visit. Who knows, maybe he'll teach him how to scuba dive and that'll be something.
He watches Izuku roll around experimentally in the bed. He watches him rub his face against pillows and rummage under the blankets and get caught up staring at the whirring fan on the ceiling.
Katsuki told him not to do it. That's important.
He told Izuku not to come back to the shore and he thought that was goodbye and he was lying here alone a week ago and crying himself to sleep about it. He told Izuku it was a bad idea and he should be happy and it's okay if that's not with Katsuki.
It was a whole speech. A good one. And it hurt.
"Kacchan, whyʼs there a bunch of stuff in here that says Bakugou on it?"
"Thatʼs my name, dumbass. They donʼt have family names in the ocean?"
Izuku shakes his head. "No. What do you use it for? Do I need one? Or can I borrow yours?"
Thereʼs plenty to pick from. Katsuki even thought about things to suggest to him. Midoriya has a nice ring to it, and it means green. Sorta fits.
Heʼd never considered that Izuku might wanna steal his family name. He doesn't mind so much.
"If you want. Or you can have your own."
Izukuʼs already moved on. "Letʼs human kiss again."
"Fine," Katsuki rolls onto his back next to him, opens his arms and waits for Izuku to jump into them, which he does.
He kisses Izukuʼs cheeks and then his soft, pink mouth.
Theyʼre not gonna get anything done around here and Katsukiʼs okay with that. Showing Izuku how to be human has been helping Katsuki remember. The good parts.
Izuku sticks his hand down his own pants. He makes a face.
"Do you have something like this?" he asks. "I can kind of see the outline through your pants."
"Itʼs a dick. And yeah...we—we both have one."
"Oh. Can I see yours?"
Katsukiʼs gonna have to teach him so much about human social conventions.
"Donʼt ask people that. Or for kisses. It's okay if you ask me. It's just not okay if it's someone else."
"I know. I know all about that," Izuku says. "I do."
Somehow Katsuki doubts it. "Yeah. Why's that?"
"It's okay with us...because weʼre married. That's what humans call it, right? When they sleep in the same bed and live together?"
That's. That's not—
"Remind me again where you get your information on humans? Besides me."
"I have a seagull friend and a crab friend. They both know a lot."
Great. Perfect. Katsuki's married now because a crab said so.
Could be worse.
Katsuki shoves his pants down, his dick bobs free and Izuku immediately rolls over to fondle it.
"Easy. Itʼs sensitive."
"Sorry. Iʼll be careful."
Like hell he will.
Izukuʼs touches turn into soft little strokes. Katsuki lifts his hips up to get more of himself in Izukuʼs hand.
"Who taught you how to do that, the seagull?"
"No, but he did say humans get bigger and flushed when theyʼre happier...down there. Because of blood flow?"
Thatʼs one way to describe it.
"Are you happy Kacchan?" Izuku asks, staring right at his cock. "You look bigger now."
"K-keep doing that," Katsuki says.
"Okay," Izuku says. "Tell me if you want me to stop. Is this good?"
Heʼs just—moving wetness back and forth. Smooth movements. Why—why wouldnʼt it be?
"Yeah."
"What about this?" Izuku asks, after a moment.
"Mm."
More. Almost. Almost.
"...and now?"
Katsuki can't even answer him. Time's gotten all slow and syrupy. Like sugar-sweet molasses.
"You're so red," Izuku says. "I've never seen you like this before."
He leans over for another kiss and as soon as Katsuki feels his warm breath and the touch of his lips it's over.
He's going to—
He's gonna—
God.
He doesn't even get the chance to warn Izuku until he's over the edge, since Izuku's kissing him and clinging to him for dear life and how is he supposed to get a word in edgewise anyhow?
Which means he has to watch Izuku marvel at his own sticky hands.
Of course he is, he's never seen anybody come before.
It shouldn't be that hot, just watching his face with that fascinated look. His damn freckles. That goddamn mouth.
"Huh," Izuku says. "Can mine do that?"
Katsuki just nods. All talked out for now.
"You looked so good. Just now," Izuku says. "Your face. It–"
"Shut up," Katsuki says. "Just. Please."
"Okay," Izuku says.
He lies back, wiping his cum-sticky hands on Katsuki's clean sheets. Then starts looking up at the ceiling, wide-eyed and ready to burst with how goddamn excited he is.
He looks so happy. So happy it's starting to get contagious.
Katsuki's even having a hard time hating himself anymore. It's so fucking annoying.
"Thank you," Katsuki says, real quiet.
"For what? For that?"
"No. God no. For being here. For not listeninʼ ta me."
"No problem," Izuku says, lying back against Katsukiʼs pillow and smiling dreamily to himself. "Itʼs pretty easy when youʼre wrong."
https://archiveofourown.org/collections/bkdkk/works/49063468