[NSFW!!!] 8 Simple Rules (for screwing my Childhood Friend) - Chapter 6

Chapter 6: "If someone falls in love, it's over."

"Uraraka and Asui... Bakugou and Midoriya..."

Izuku glanced over to where Katsuki was standing with his friends, smiling awkwardly when the scarlet eyes darted his way for a moment. He didn't seem impressed by the prospect of partnering up, but it was becoming a more common event in their lives, and he'd given up arguing about it.

"Fuck off, Shitty-hair," Katsuki scowled, when the list came to an end and people began to join up with their partners. "Get out of my face."

"Don't be like that, Blasty," Denki laughed, shoving at Katsuki's side playfully. "Lighten up a little."

"Is everything okay?" Izuku asked, watching two pairs of wide eyes dart his way, then quickly back to Katsuki. "What's wrong, Kacchan?"

"Fuckin' Shitty-hair thinks he can take the bench first," Katsuki growled. "He knows I have dibs on benching first."

"Just playing around," Eijirou laughed, softening a little. "Come on, Kaminari, let's leave them to their benching."

"You sure everything is okay?" Izuku asked, when the pair had wandered out of earshot, giggling about something together. "You seem... off."

"It's fine."

"Okay! You wanna go first or should I?"

"You can."

Izuku set his water bottle aside and lay down on the padded bench, letting Katsuki slide the plates into place while he got set up. There was something almost comforting about how well they knew each others' routines at this point, how they never had to discuss or argue or direct, they could finally just get on with it. It wasn't like the day Izuku was paired up with Eijirou, who had easily managed to assist with Izuku's weights, but had also talked his ear off the entire time he worked, leaving Izuku distracted. And it certainly wasn't like the day he'd been partnered with Uraraka, who had resorted to using her quirk when she'd panicked and pulled a weight off him early – he appreciated the concern, of course, but there were few things more embarrassing than having your weight pulled off in the middle of a class-wide workout session.

"I'm adding one," Katsuki informed him, as he reached for the smallest plates to add to the bar. "You've been doing twenties with no issue, go for fifteen tougher ones."

"Got it!"

His baggy sleeves fell back as he curled his fingers around the bar, and in a strange moment of unthinking, Katsuki reached down to adjust one where it pulled tight, freeing up his range of motion. He seemed to think better of it halfway through the act, his eyes darting to the shining green ones below, silently staring at each other.

"Thanks," Izuku said finally, smiling fondly. "Okay, fifteen, let's go!"

"Dork."

Katsuki sat back to watch, always close enough to step in if needed, but showing no sign of ever planning on it. He trusted Izuku to handle it, trusted that he was never going to take something on that was above himself. If anything he was the opposite, always lifting less than he was capable of for fear of failure. It was his more private sessions where he pushed, when there were only a few people in the gym, late at night after most of the students had gone to bed. Katsuki had seen him there on occasion, on nights when he couldn't sleep. Sweating his ass off with no one around to see it, only a quick burst of One For All to save him when it got to be too much.

Maybe that was the real reason Katsuki never worried about spotting closely, he'd seen the way the nerd bailed, and it was far more impressive than their classmates' pathetic failures.

Before he knew it, Izuku was climbing to his feet, wiping his face briefly on his towel when he pulled it off the bench.

"Give me a heavy load," he requested, when Izuku loosened the fastener to change the plates. "I want to go to failure, so you better have your ass ready."

"Of course, Kacchan! I'd never let it fall on you!"

That, too, was a familiar routine. When it came to squats or cardio, Katsuki couldn't care less about his weights, but benching? No, arms were a serious matter in Katsuki's life. The stronger his arms were, the better his quirk would work. That was serious business if he'd ever seen it.

"Same as last time?" Izuku asked, thinking back to a few nights prior when Katsuki had shown up bleary-eyed at three a.m. and Izuku had quickly stepped in when he saw the weights stack up. "Or even more?"

"You're the nerd here, gimme whatever."

With a little smile Izuku stacked on the same plates they'd used the time prior, crouching beside Katsuki's head when everything was in place.

"You trying to impress me all of a sudden?" he teased. "It's not like you to give me free reign."

"Fuck off, if I wanted to impress you it wouldn't be in the gym. I know you're already perving at me in here."

Izuku laughed, clear and bright like a church bell ringing in the distance, or a fresh breeze through the trees on a sunny morning, or- Fuck, no wonder Katsuki's friends made fun of him. He'd gotten too affectionate toward the nerd, so blinded by the decent sex that he'd all but forgotten all his assholery and annoying qualities, the way he ran in like a fool at the slightest sign of danger, or landed himself in hospital because he couldn't just listen for once.

"Fucking whatever," Katsuki grumbled, lifting the bar off the rack and bringing it down to his chest. "Just pay attention, you dumb fuck. Don't go getting distracted while I'm lifting double your weight."

"Uh-huh," Izuku smirked, "if you wanted double my weight you should have said so. I'm not sure if there are enough plates in the gym but maybe I could find some more somewhere."

"When did you become a stuck-up asshole?" Katsuki snorted. "We could triple your weight with that rack alone."

"I learned from the best!"

"Shut the hell up."

Izuku grinned, but shut his mouth all the same, letting Katsuki focus on his work. It was kind of impressive to watch, if he was entirely honest. He would have to use his quirk to bench the same weights Katsuki did every day – sure, he would catch up one day, but no doubt Katsuki would somehow be lifting even more by then.

He made it to eight repetitions before his arms began to shake, and Izuku grinned down at him cheekily. Katsuki saw the teasing coming and grimaced, his hands stalling, and Izuku hummed softly to himself, feigning contemplation.

"Just two more, Kacchan. You can do it, can't you?" he asked, bending down closer again. "You'll do it for me, won't you? You look so good all sweaty and strong like this, you gonna be a good boy and finish your set for me?"

"Fuck you," Katsuki grunted, forcing the bar all the way up. "I could keep going for hours."

"Uh-huh, I'm sure you could. Kacchan is so strong. So amazing."

"Shut your fuckin' mouth."

Izuku giggled, watching fondly as Katsuki forced out his final rep and got the bar back on the rack, scowling as he sat up and adjusted his pants briefly. Izuku knew that face, that stubborn look that he couldn't quite call genuine annoyance, and he waited patiently for Katsuki to get up of his own volition, rather than start to switch places right away.

"You're an asshole," Katsuki scowled, when they finally swapped. "Trying to get me all pent up when I can't do anything about it for hours?"

"It's just so much fun to torture you, Kacchan."

"Fuck you."

"Maybe later."

─────

Katsuki's eyes widened when he saw the gag in Izuku's hand. He'd been threatening it for a long time, to muffle Katsuki's cursing, but he'd never expected the nerd to actually go through with it. He shook his head faintly as Izuku leaned in, spitting curse words, but Izuku only smirked at him as he nipped at Katsuki's tender neck.

"It's about time you learn how to talk to Master," Izuku said in a low voice. It was surprisingly hot, Katsuki couldn't help but notice, but the gag in that scarred hand still made him tense. "What's that old saying? If you don't have anything nice to say, don't say anything at all?"

"B-But-"

"Hmm? You arguing with Master?"

He shook his head wildly, and Izuku smirked against his neck, coaxing the fabric over Katsuki's mouth and reaching behind his head to tie it in place.

"N-No. No, don't, I- I'm not- Why am I- F-Fuck, fuck, fuck. Shit! K-Katsudon!"

Izuku yelped, tearing it off in a hurry before he'd even begun to knot it, throwing the offending material across the room with a vengeance. He pushed himself up to see Katsuki's sweaty face, his glistening eyes, his pupils blown so wide he could hardly even see the red anymore.

"I'm sorry," he said quickly, oddly breathless. "Talk to me, Kacchan. Are you okay?"

He nodded faintly, and Izuku moved a shaking hand to Katsuki's hair, stroking him lightly.

"Talk to me, baby. What's wrong? I promise I won't do it again. The gag was too much?"

Katsuki nodded.

"I need to hear your voice. Please, Kacchan."

"I j-just- Fffffuck. I don't..."

"Good boy, good boy. You're so good, Kacchan, so good. I'm so proud of you for using the word, okay?"

"You're not d-disappointed?"

"What?! No! Kacchan! Never! This is exactly why we've had a safeword all this time. I would never be disappointed in you for using it. Never hesitate, okay? I'm so proud of you, my good boy."

Katsuki nodded faintly, his breaths evening out, and Izuku continued to stroke at his hair gently as he moved aside and lowered himself to the mattress.

"Is it the sports festival thing?" he asked quietly. "I know you're still really upset about it, so I would understand."

"It wasn't that."

"Okay. Just an aversion, huh? It's okay."

"It was the s-sludge v-villain."

Izuku froze, images flashing through his mind. He'd been so focussed on All Might, on himself, he'd never thought about how truly traumatic it must have been for Katsuki. He hated himself for that.

"I understand," he said finally, running his hand down to Katsuki's cheek, sharing his warmth with the oddly cold skin. "I was only held by it for moments, and it was... I don't know how you were so strong, Kacchan. You're amazing."

"I'm normally fine," he mumbled. "The sports festival brought it up a little, or I wouldn't have been so..."

"I'm so sorry, Kacchan."

"And then when you covered my mouth, I just... Panicked, I guess."

"Thank you for talking to me, Kacchan. Thank you so, so much. I never knew. I'm so sorry I made you feel that way. I promise it will never, ever happen again."

Katsuki nodded, and Izuku moved a little closer.

"Can I hug you?"

"Yeah."

He gently wrapped his arms around Katsuki's waist, a little surprised at how fragile he suddenly felt. Katsuki rolled over into his grip, snuggling into Izuku's chest, and Izuku smiled faintly as he gently rubbed at tense back muscles.

"I want you to trust me, Kacchan."

"I do."

"It must have taken a hit, though, after this whole thing."

Katsuki shook his head, refusing to lift it from Izuku's chest.

"You stopped."

"Of course I stopped!"

"I still trust you, because you stopped."

"Yeah?"

He nodded this time, sighing faintly, his breath warm on Izuku's skin.

"You took me seriously," he murmured. "You could have... I don't know, said it was stupid, or talked me into trying it anyway. You didn't, though, you just immediately cancelled that idea and put it on the 'never again' list."

"I always will, Kacchan. If you're not comfortable, I will always stop. I promise."

"That's why I still trust you."

Izuku smiled, leaning down to plant the tiniest kiss on blond spikes, squeezing him a little tighter.

"We don't do this much," he whispered into the soft hair. "Want to snuggle tonight?"

Katsuki nodded, and Izuku freed one arm to switch off the bedside lamp, pulling the blankets up to cover their nude, huddled forms. He smiled fondly as he closed his eyes, feeling Katsuki soften into him, and for a moment neither of them spoke.

"Sweet dreams, Kacchan. You can wake me up if you need me, okay? If..."

"Yeah," Katsuki nodded. "I will."

"Good boy."

─────

Things seemed to gradually settle back to normal, after their night of affection. Neither of them mentioned it again, but gags – and restraints in general, Izuku had decided, even if he never said the words to Katsuki – had been struck from the list of toys, never to return unless Katsuki very specifically and adamantly requested it. They fooled around again. Multiple times. Every night. Multiple times every night.

Until...

For the first time ever, the sex was bad.

Katsuski struggled to get that concept through his head, as they lay side-by-side, neither of them daring to speak as they stared at the roof in silence. Part of him wanted to bolt, wanted to disappear and pretend it never happened, but some small part of him knew they needed to find the words. Even his momentary trauma and subsequent safeword usage hadn't been as much of a shitshow as this.

"Well, that was awkward."

Good job Katsuki, you fucking idiot.

"I mean-"

"No, you're right," Izuku nodded. "I think we both had stuff on our minds, yeah?"

"Yeah."

"We should probably talk about it."

"Why do you think I'm still here, shitty nerd?"

Inexplicably, Izuku smiled. He rolled onto his side, propping his head on his hand, and had the gall to god-damn smile at this shit.

"Do you want to go first?"

"No."

"Should I talk, then?"

"I guess so."

Izuku's smile wobbled slightly, and Katsuki revelled in the knowledge that he wasn't as composed as he seemed.

"My friends are starting to suspect something."

Katsuki's eyes widened, but he remained silent.

"Uraraka won't stop fawning over it, going on about 'Deku's crush on Bakugou' and 'you've been together so long, you must be soulmates' and all this sappy bullshit you would be disgusted by. Even Iida is giving me lectures on keeping myself safe, although Todoroki stood up for you when Iida tried to imply you were abusive to me."

"I kind of was."

"Maybe once or twice, on the really bad days, but that was a long time ago. I would never let anyone compare you to a piece of shit like Endeavor. Todoroki either."

"He's alright."

"Endeavor?!"

"Half-and-half, you dumb piece of shit! Like I'd ever call that mound of human turd alright."

Izuku giggled, and Katsuki softened a little to hear it. He never thought he would miss hearing Izuku laugh in the bedroom, but really that sound summed up their entire arrangement. They were having fun, whatever that meant for each of them. Trying to have sex without hearing it had been a strangely weird experience.

"Mine too," he said finally. "Shitty-hair and dunce-face won't shut up about how much time I've been spending with you."

"Are you serious?!" Izuku rose up on his arm to see Katsuki's face, laughing again already. "Your friends are giving you shit as well?"

"I wouldn't call them my friends."

"Honesty, Kacchan. Stop breaking rules over silly things."

That rule went out the window before it was even made.

"Whatever," Katsuki grumbled, rolling over to face the wall. "They're just shitty classmates who want to torment me or whatever."

"We were in the same boat and never even realised," Izuku giggled. "That's so like us."

Not the exact same boat, his brain so helpfully supplied. Stop lying, Izuku. You demanded honesty.

In a moment of weakness, Izuku snuggled into Katsuki's back, breathing in the sweet scent of his quirk-sweat.

"Wanna try again?" he asked, a hint of teasing in his voice.

"What are we gonna do if it happens?" Katsuki asked quietly. "If... If you really do end up with a crush on me, I mean. I wouldn't blame you, just look at me, right? I'm surprised you haven't already."

Izuku's heart pounded, and he quickly levered himself up again, ensuring Katsuki wouldn't feel the rapid beat against his back.

"Then I lose, right? That was one of the first rules we set."

"But what does that mean? You lose, sure, but then what happens to... This? If one of us has a crush and the other is just screwing around still, what are we meant to do?"

"I guess I assumed it would be over," Izuku said softly. "When someone falls in love, it's over."

"Yeah, I guess so," Katsuki agreed breathlessly. "Rule Six, huh?"

Izuku hummed his reluctant agreement, gently brushing his fingertips over Katsuki's tense shoulder.

"Yeah. Rule Six."

Izuku hesitated, gritting his teeth and squeezing his eyes shut, willing his voice to stay steady.

"Are you worried, Kacchan?" he asked slowly. "Because I... I don't, okay? We're just..."

"Fooling around."

"Yeah. That's all I want from you. Fun and sex."

Lies, lies, lies.

"Yeah, me too."

Lies, lies, lies.

"So, uh, that's sorted," Izuku mumbled.

"Yeah. I should head back."

"Already?"

"Mm. Kind of tired tonight, after that whole... Thing."

"Okay. I hope you sleep well, Kacchan. Sweet dreams!"

"Whatever."

He hauled himself off the bed, dressing in his discarded clothing from earlier, and Izuku watched sadly as he left without even looking back. He wasn't mad, Izuku could read him better than that, but he was certainly still awkward. Maybe he would sleep it off, maybe next time would be better.

Izuku certainly hoped so. It wasn't worth breaking a rule so blatantly for this.