Katsuki Bakugou was never an indoor person. Being inside irritates him. Since childhood, he's always preferred playing outside than staying in the house. There was never much for him to do at home. Being outside meant he could go into the forest or play at the riverside. Being inside meant sitting through hours of educational channels his mother forced him to watch. Besides, as he grew older and started training (?) his quirk, his mother didn't allow him inside anymore, since she valued her furniture more than the future success of her son. Or so he wrote in his pre-teen diary. Yes, Katsuki Bakugou had a pre-teen diary, that he burned to crisps, along with every single strand of hair of the unlucky kid who discovered the notebook by accident.
No, he is definitely not an indoor person, but if staying inside means half-lying on his couch, remote in one hand, zapping idly through different channels on the television; the other hand caressing Izuku's fluffy hair while the latter slowly kisses up his naked chest, then Katsuki has no complaints.
Katsuki's parents were on a business trip to another city so he had the house all to himself until morning. Since he wasn't permitted to leave the house, he had to find another way to battle boredom. And what better way to kill off Sunday afternoon's drowsiness than to call his boyfriend, who is literally one block away, over.
Izuku wasn't surprised to hear Mr. and Mrs. Bakugou were away and that Katsuki had to look after the house again, but he was quite shocked to be invited over. Ever since they began dating, the two have mostly been spending time at Izuku's place. Katsuki isn't the type to invite people over to his house, and even though Izuku has visited before, he never expected to be called over this sudden.
"This is kind of sudden, Kacchan, I'm working on something right now…"
"I'm horny, so hurry the fuck up."
"Oh. Okay."
Katsuki isn't the type to be subtle.
So Izuku abandoned his one-hour work on the newest Silver Age All Might limited edition action figure he recently acquired, put on a jacket, and got out of the house. Or so he told Katsuki.
And that was how Katsuki found himself in the current position, where he tries his best to maintain his calm and not to drop down and moan every time Izuku moves his lips to another spot on his upper body. He would never admit it, but he likes the way Izuku kisses. He never thought Izuku would be an attentive kisser, but given the way the kid never half-assed anything, he really shouldn't be surprised. He remembers back when they first started dating and Izuku made it his life's mission to show Katsuki his affection every day, by bringing him food and making sure he was properly hydrated in gym class. It started out cute, and he was pleased with the attention, but with Izuku's personality, it somehow became an obsession, to the point where Katsuki threatened to end their relationship "if you don't stop smothering me with all these 'care packs' every afternoon, also your cookies fucking suck".
He gets pulled out of his thoughts when Izuku starts sucking on his left nipple, which sends a tingling sensation straight to his nether region. With one hand gripping into Izuku's hair, he half-throws the remote on his other hand down the coffee table, the TV screen long forgotten. He hikes his right thigh up as Izuku grinds down at his crotch, earning a delicious gasp from his mouth. He can feel the fucker smirking against his chest as he moves enthusiastically to Katsuki's unattended right side.
The house is quiet save for the sound of them kissing and panting. Katsuki can feel himself getting visibly hard, and Izuku is not far behind, either. He puts one hand on Izuku's back and starts trailing down to grab at his ass. His other hand continues its work of trying to uncurl Izuku's ridiculously curly hair. As he tries once again to smooth down that one particular strand, he suddenly feels a sharp pain on his neck. Immediately, he yanks on Izuku's collar to get him off, yelling at the same time:
"What are you doing? That hurts!"
Izuku, startled by Katsuki's booming voice against his ear, pulled back with a dumbfounded look on his face:
"What's wrong? Did I do something?"
"You fucking bit me!"
Katsuki can feel the pain starting to spread. What the hell are this guy's teeth made of?
"I did? So-sorry about that, I didn't realize what I was doi-ieeeekkkk!"
"What now?"
"Oh God, you…you are bleeding, Kacchan!"
"What?"
Katsuki picks up his phone on the table and looks into the front camera. Just like Izuku said, the place where the latter bit him is slowly reddening and tiny drops of blood are breaking out. He looks like he got bitten by some sort of savage animal in the wild. Or maybe he did get bitten by some sort of savage animal in the wild.
"Damn it, Izuku…" He grumbled loudly, putting his phone down. Next to him, Izuku is starting to fumble furiously, not being able to calm down after realizing he has bitten Katsuki hard enough to bleed.
Katsuki slaps him lightly on the face.
"Calm the fuck down, I'm not dead."
"Bu-bu-but…"
"The bleeding will stop, and you're a pathetic excuse of a boyfriend if you get excited enough you can't control your fucking mouth. And here I thought Kirishima had freaky teeth."
Their makeout session is abruptly stopped in order for Katsuki to seek medical attention. He tells Izuku to stay put and heads to the bathroom. As he gets a closer look of his neck in the mirror, Katsuki notices that not only the place where he got bitten is turning into an ugly blotch, other marks in various shades of red and purple are starting to form around his collarbone and his upper chest. It looks like Izuku gnawed on him. They have left marks of all kinds on each other's bodies while fooling around before, but never have Katsuki seen his skin this colorful. And people think he's the beast in the relationship.
"Kacchan, are you ok?"
As usual, his boyfriend has troubles doing as he's told. Izuku has entered the bathroom and is standing right behind Katsuki, putting a hand on his shoulder.
"Wow, did I-did I do that?"
Katsuki throws him the most sarcastic look he could ever manifest in his life.
"No, I did that to myself just a second ago. Of course it's your fault, dumbass!"
"Don't call me that…"
"You're a dumbass because you did something stupid. Look at me, I look like I have some fucking skin disease!"
Much to his annoyance, Izuku's face breaks into a smile.
"I think you're beautiful."
Katsuki can feel the heat rising to his head, his cheeks specifically, but he doesn't know if it's from anger or embarrassment because how the hell do you manage to say that with a straight face.
"I mean, you look like a painting, Kacchan, Plus, it's not the first time you have, um, hickeys on your body. You can cover it with your clothes."
"Not when they are fucking everywhere like this! What if we have hero class? My costume barely covers anything!"
"And I thank the costume department everyday for that."
"You fucking-" Katsuki can feel a vein popping in his head. "You're not in the least sorry about this, aren't you?"
"About biting you, yes, totally. But other than that…yeah, not really."
Katsuki debates over what he wants to do right now. Izuku's shit-eating grin makes him want to punch him to oblivion and throw his body out of the window, but that would result in homicide and he, as a hero-in-training, can't afford to have that on his record. He also wants Izuku to live. Blowing Izuku's face up sounds tempting, but that would trigger unpleasant memories for them. He has sworn to never use his quirk on Izuku again. He could hit Izuku with the broom, but he's afraid of breaking the lamps and having his mother roast him.
Instead, he kicks Izuku out of the house. Literally. With his shirt on, of course, he doesn't need any of his neighbors seeing him in that state.
-oOo-
The next morning, Katsuki's parents go home to a scream. After running up the stairs, knocking on their only son's door and receiving "It's none of your business, you shitty old couple!" as a response, they dub it as his son's usual hormonal fit and retreat back to their room. Oblivious to them, Katsuki Bakugou is in agony for a very valid reason, as he finds out that the aftermath of his and Izuku's incomplete makeout session yesterday hasn't faded away and is still very much present. He managed to cover up his chest by wearing an extra shirt under his uniform, but the bite mark Izuku graciously left him is impossible to cover up with a normal shirt, and he isn't wearing a fucking turtleneck. Not like he owns one anyway.
He considers staying at home today, but he will miss out on seeing Izuku and punching the hell out of that damned nerd. He will also miss gym class, where he can stretch his body and punch Kirishima for stress relief, because only punching Izuku won't be enough. He surely can't stay home.
He takes another good look of himself in the mirror. The hickey is on the right side of his neck, a little above the collarbone. His uniform collar can cover it from a certain angle, but not properly. He would have to hold it up a little higher.
He tries once again to weigh the pros and cons of skipping class, but there is no way his mother is letting him anyway.
He curses every single being in this world he can identify, before opening the bottom drawer of his closet and pulls out the piece of cloth he has neglected on purpose ever since high school started.
-oOo-
That day at Yuuei, the teachers almost had to call security reinforcement when they heard the uproar coming from the Hero Department. Kids were running out, crying and laughing at the same time so the staff thought they were hit by a mind-controlling quirk or something. All Might flew out of his bed to come aid his colleagues, but got pushed back by Aizawa when he couldn't even climb the stairs without spurting out blood.
Turns out there wasn't any villain coming to raid Yuuei.
Turns out, that day, Katsuki Bakugou came to school with a tie on his neck, got stared at, got mocked, raged, punched Izuku Midoriya, punched another kid when he saw Midoriya was still standing, got his tie undone and the mark on his skin exposed by accident, blushed, raged again, exploded a few chairs and desks, broke the classroom door, forced a few people's quirks to activate, and managed to trigger Todoroki's quirk that froze the entire class and half the adjacent room.
Katsuki Bakugou was restrained seven minutes after, but the damage he caused earned him three days of detention, a(nother) red mark in his record and a three-hours lecture by All Might in Aizawa's office, all while being tied up.
-oOo-
"Thank you for your work!"
"You're welcome, kid. Get home safely, okay?"
"I will!"
As Izuku gets out of the school infirmary, he feels exhausted. Today was a very eventful day. He knows how strong his boyfriend's quirk is, he was the victim many times, but he never imagined the full extent of the destructiveness that is Katsuki Bakugou. As one of the few sane persons left after the event, he had to carry the injured to the infirmary, along with whatever those whose quirks were activated left them with. Most of his classmates only had to seek medical attention for frostbites; but some girls had to go home early to rest. Class B was involved too. He rethinks his life choices and maybe, just maybe, pissing Katsuki off isn't a very good idea after all.
He didn't expect to see Katsuki waiting for him at the school gate with a scorned look on his face. As Izuku approaches him, his face seems to light up a little bit.
"Kacchan! All Might let you go already? Are you okay?"
"Do I look okay to you?"
Izuku gives him a once over.
"You're still in one piece. The last time All Might lectured me I got punched in the face."
"That's because you weren't tied up and chained to the chair."
"Did they also muzzle you?"
"Why the fuck-no, not this time".
Izuku pats him on the cheek.
"I'm sorry I bit you and got hickeys all over your body."
Katsuki's right eyebrow rose up.
"And?"
"…and for not defending your virtue when you are teased by ever-that hurts, Kacchan!"
"I don't need that kind of sorry!"
Putting both his hands up to cover his violated cheeks, Izuku pouts.
"You should also apologize to me. You punched me, Kacchan."
"You fucking deserved it, nerd."
Izuku looks him straight in the eyes.
"…I'm sorry for punching you in the face. It was not very satisfying anyway."
The punch wasn't enough to satisfy Katsuki's rage. Izuku's smile, however, is probably enough to appease it.
-oOo-
They get to walking because it's gotten quite late, and Katsuki has a curfew. His parents won't be home until late, so he invites Izuku to come over again. Izuku eagerly accepts.
They arrive at the Bakugou household a little after six. Katsuki leads Izuku to his bedroom, because he doesn't know exactly when his parents will be home. As much as he loves his parents (although he will never admit it), he doesn't want them to find out about their relationship just yet. Not until he's graduated and gotten a decent job that could guarantee him an independent life. That way, even if he were to be chased out of the house with a broom breaking the news to his parents, he would have a place to go. Preferably an apartment because he would never be able to take care of a house.
Preferably with Izuku.
Speaking of Izuku, he watches as the boy slowly closes in on him with his eyes shut and his lips slightly parted. Izuku wants to be kissed. Any other day, he would gladly oblige. He is never opposed to the idea of kissing Izuku, especially when they are alone.
However, today he has other plans. True to his words, Katsuki Bakugou's rage can't be satisfied with a few punches, even if you throw in a frozen mob of his idiot classmates. Oh no.
Placing both hands on Izuku's waist, Katsuki quickly proceeds to swoop his boyfriend up and throw him ceremoniously on the bed with a thud. Startled, Izuku looks at him with questioning eyes. Leaning down, Katsuki undoes his tie, and smirks.
"Payback time."