Chapter 13: Sparring Session Gone Wrong
The gym at the Endeavor Agency annex was a cathedral of exertion. The air hummed with the grind of plates, the rhythmic thud of fists on heavy bags, and the low murmur of heroes discussing tactics between sets. Sunlight streamed through high windows, catching the dust motes and the sheen of sweat on corded muscle.
In a corner mat, Katsuki and Izuku were a blur of controlled violence.
It wasn’t a friendly spar. It never was with them. It was a conversation in a language of impact and leverage. Izuku shot forward, a green-licked dart, aiming a low sweep. Katsuki anticipated it, launching himself over the leg and bringing an elbow down where Izuku’s head had been a fraction of a second before. The mat shuddered.
“Too slow, nerd!” Katsuki barked, but there was a feral grin on his face.
Izuku rolled, springing up with a burst of One for All that made the air crackle. “Your right side’s open, Kacchan!”
“The hell it is!”
They closed again. Block, parry, a grapple for dominance. Katsuki caught Izuku’s wrist, twisting, using his weight to drive him backward. Izuku’s heel hit the edge of the mat, balance compromised. With a grunt, Katsuki leveraged him down, following him to the floor.
The takedown was clean, professional. What happened next wasn’t.
Izuku’s back hit the mat, Katsuki landing atop him, knees bracketing his hips, one hand still pinning Izuku’s wrist above his head. They were both breathing hard, chests heaving. The air between them changed. The competitive fire banked, replaced by something hotter, more specific. Katsuki’s free hand, which had been poised to deliver a mock knockout tap, instead splayed across Izuku’s sternum, feeling the frantic rabbit-thump of his heart.
Izuku went still. His breathing hitched. A flush, deep and rosy, spread from his face down his neck, disappearing under the damp collar of his training shirt. He didn’t struggle.
Katsuki leaned down, his own breath gusting over Izuku’s parted lips. His voice dropped to a graveled murmur only Izuku could hear. “See? Told you your right side was a fucking problem.”
It was then, in that loaded silence where the gym’s noise faded to a distant buzz, that someone cleared their throat. Not a casual sound. A sharp, deliberate, disapproving ahem.
Katsuki’s head snapped up. Tenya Iida stood at the edge of the mat, his glasses glinting, arms crossed rigidly over his chest. His posture was a textbook of perfect disapproval. He must have just returned from his trip; he still had the air of someone who hadn’t fully decompressed from a mission.
Katsuki didn’t move. He didn’t release Izuku’s wrist. If anything, his grip tightened, a possessive reflex. His red eyes narrowed. “Problem, Four-Eyes?”
Iida’s jaw tightened. “This is a public training facility, Bakugou. Not a… private grappling studio.” His eyes flicked to Izuku, who looked like he wanted the mat to swallow him whole. “Midoriya. Are you… conceding the match?”
Izuku made a small, choked sound. “I, uh—”
“The match isn’t over,” Katsuki cut in, his voice low and dangerous. He finally shifted, but only to adjust his weight, his knees pressing more firmly into Izuku’s thighs. A clear, unspoken signal. Stay put. “We’re discussing technique. Something you wouldn’t know about with your stiff, by-the-book bullshit.”
“My ‘bullshit,’ as you crudely put it, maintains professionalism and safety!” Iida’s voice rose, chopping the air with his hand. “What you are exhibiting is neither! Your positioning is unnecessarily intimate, and your conduct is distracting to others!”
A few heads had turned. A sidekick on a nearby treadmill slowed to a walk, watching.
Katsuki felt the old, familiar fury start to boil. The public scrutiny, the judgment. It clawed at the fragile peace he’d carved out with Izuku, the private understanding they’d sealed on his apartment floor just days before. He bared his teeth. “Why don’t you take your professionalism and stick it up your—”
“Kacchan.” Izuku’s voice was quiet, but firm. He pushed against Katsuki’s chest, not hard, but insistently. “Get off.”
The use of the command, so rarely directed at him, cut through the red haze. Katsuki glared down at him, saw the pleading embarrassment in those green eyes, and relented with a scoff. He shoved himself up and off in one fluid motion, standing and offering a hand he knew Izuku wouldn’t take in front of Iida.
Izuku got to his feet on his own, brushing imaginary dust from his pants. His face was still flaming. “Iida, it’s good to see you back. How was the mission in Kyushu?”
“Successful, thank you for asking,” Iida said, his tone cooling only a degree. He wasn’t going to be derailed. “Midoriya. A word. In private.” His gaze swept to Katsuki, a clear dismissal.
“Anything you have to say to him, you can say in front of me,” Katsuki growled, stepping closer to Izuku’s side.
“It’s okay, Kacchan,” Izuku said, placing a tentative hand on his arm. The touch was a catalyst and a coolant all at once. “Go grab a shower. I’ll catch up.”
For a long second, Katsuki looked like he might refuse. His eyes darted between Izuku’s resolute, embarrassed face and Iida’s rigid, concerned one. He saw the conflict, the unwanted intervention. With a final, searing glance at Iida that promised later consequences, he turned and stalked away towards the locker room, his shoulders a tense line.
Iida led Izuku to a relatively quiet alcove near the water coolers. The hum of the gym was a buffer here.
“Midoriya,” Iida began, his voice lower now, edged with genuine worry. “What is going on?”
“Nothing’s ‘going on,’” Izuku said, too quickly. He took a long drink from his bottle, avoiding Iida’s eyes. “We were just sparring hard. You know how Kacchan gets.”
“I know how Bakugou gets. I am less certain I know how you get.” Iida adjusted his glasses. “What I witnessed was not standard sparring protocol. The energy was… different. And this is not the first time Uraraka has expressed concern. She says you’ve been distant, and that you and Bakugou are… spending a significant amount of non-combat time together.”
Izuku’s stomach dropped. Ochaco had noticed. Of course she had.
“We’re friends,” Izuku insisted, the word tasting like ash. “We work closely. It’s not… it’s not against any rules.”
“It is against the spirit of professionalism if it compromises your focus or creates a perception of favoritism!” Iida’s hand chopped the air again, a nervous habit. “And more importantly, as your friend, I am concerned. Bakugou is… volatile. His treatment of you has a long and complex history. To see you in such a physically subordinate position, and to see you blush in that context…” He trailed off, struggling for the right words. “It does not appear consensual in a professional, or even a friendly, sense.”
“It is,” Izuku said, his own voice gaining strength. He met Iida’s gaze. “It’s completely consensual. You don’t understand the context.”
“Then help me understand!” Iida’s voice softened, pleading now. “Is he pressuring you? Because if this is some new form of rivalry or dominance game he’s—”
“It’s not a game.” The words burst out of Izuku, raw and frustrated. He thought of the therapy sessions Katsuki was attending, the confession on the floor, the terrifying, beautiful honesty in the dark. “It’s… complicated. But it’s not what you think. He’s not… he’s trying.”
Iida studied him, seeing the fervent defense, the protective glow even amidst the embarrassment. His stern expression melted into one of dawning, profound worry. “Oh,” he said quietly. “Oh, I see.”
Izuku knew that tone. It was the sound of Iida connecting dots, and the picture he was forming was terrifyingly accurate.
“Midoriya,” Iida said, choosing his words with immense care. “If this is a personal relationship… that is, of course, your private business. But pursuing it in secret, within the confines of our agency, with someone of Bakugou’s temperament… The potential for emotional collateral damage is severe. For both of you. And if it were to become public knowledge amidst a media climate that already scrutinizes your every move…”
“I know,” Izuku whispered, the fight draining out of him. He leaned against the cool wall. “I know all of that.”
“Does he?” Iida asked, point-blank. “Does Bakugou understand the risks, or is he simply acting on impulse? Does he understand what you might need from this? From him?”
The question was a needle to the heart. Izuku thought of Katsuki’s language—the searing kisses, the punishing possession, the physical claims that stood in for words he couldn’t say. It was a language Izuku spoke too, now. But it wasn’t the only one he needed.
“He’s learning,” Izuku said again, but it sounded weaker this time, a hope more than a certainty.
Iida placed a firm hand on his shoulder. “Be careful. Please. And for heaven’s sake, if this is something real, establish some boundaries. Not just for your reputation, but for your heart.” He gave the shoulder a squeeze before turning to leave. “I will speak to Uraraka. She is worried, not suspicious. We care about you.”
Izuku stood alone by the water coolers, the chill from the wall seeping through his shirt. He could still feel the ghost of Katsuki’s weight on him, the heat of his hand. He could still hear Iida’s clinical dissection of the risks.
When he finally made it to the locker room, it was empty except for the sound of showers. He rounded the corner of the bank of lockers.
Katsuki was there, leaning against his closed locker, dressed in fresh black jeans and a tight gray shirt, arms crossed. He wasn’t looking at Izuku. He was staring at a crack in the tile floor, but his entire body was coiled, listening. The steam from the showers curled around him.
He’d heard every word.
He lifted his head. His eyes were dark, unreadable. No fury, no sarcasm. Just a flat, waiting intensity.
“Well?” Katsuki’s voice echoed softly in the tiled room. “What’s the verdict from the morality police?”
Izuku’s breath caught. This was the cliff’s edge. He could back away, make a joke, defuse it. Or he could step into the void.
He took a step forward. “He’s worried about me.”
“Obviously.”
Another step. “He thinks you’re a volatile risk. That this…” He gestured between them. “…is a secrecy-shame spiral waiting to blow up.”
Katsuki didn’t deny it. He just watched him, a muscle ticking in his jaw.
Izuku stopped in front of him, close enough to touch. He could smell his own soap on Katsuki’s skin. “He asked me if you understood what I needed from this. From you.”
The air went still. The only sound was the drip of a distant showerhead.
Katsuki’s gaze finally lifted, locking onto his. The flatness was gone, replaced by something stormy and vulnerable. “And what did you tell him?”
Izuku held that turbulent red stare. He thought of the fear, the possession, the therapy, the floor. He thought of the unspoken want that ached in him constantly.
“I told him you were learning,” Izuku said, his voice barely above a whisper. “But I didn’t tell him what I need.”
Katsuki pushed off the locker. He didn’t reach for Izuku. He just stood there, in the space between confession and action, waiting. The question hung, heavier than any physical weight.
Izuku took the final step, closing the distance until their chests almost touched. He looked up, his own need stripping him bare. “I need you to stop pretending this is just a game we’re playing in the dark.”
Katsuki’s breath hitched, a sharp, quiet sound in the damp air. He didn’t look away. The storm in his eyes churned, and for a terrifying second, Izuku thought he’d miscalculated, that the vulnerability would be met with detonation.
Then Katsuki’s shoulders slumped, a minute surrender. “It’s not a game.” The admission was rough, forced out. “It’s a fucking minefield. You know that. Iida knows that. Everyone with eyes knows that.”
“I don’t care what they know,” Izuku said, his own resolve hardening. “I care what we do. About how we navigate it.”
“By doing what? Holding hands in public? Putting a bow on it?” Katsuki’s lip curled, but the sneer lacked its usual heat. It was defensive, a reflex.
“No.” Izuku shook his head. The steam was making his curls stick to his forehead. “By being smarter. By not getting caught with your pants down, literally, in a place where anyone could walk in.”
A flicker of understanding. The gym. Iida. The exposed moment on the mats. Katsuki’s jaw worked. “He interrupted a spar.”
“It wasn’t just a spar and you know it.” Izuku’s voice dropped, earnest. “The way you looked at me… the way you didn’t get up. Kacchan, we can’t… we can’t blur the lines like that out there. It’s dangerous.”
“Dangerous,” Katsuki repeated, the word tasting foreign. He associated danger with villains, with collapsing buildings, not with the slide of his hand over Izuku’s hip.
“For our careers. For this.” Izuku gestured between them again, a smaller, more intimate motion. “So I think we should set some boundaries for our sex life.”
Katsuki went very still. The word ‘boundaries’ seemed to physically grate against him. “Boundaries.”
“Yes.” Izuku took a steadying breath, channeling the same focus he used for mission planning. “Rule one: no sex outside the confines of our own homes. My apartment or yours. Nowhere else. Not in agency showers, not on patrol rooftops, not in supply closets.”
“You’re joking.” Katsuki stared at him, incredulous. “That’s half the fun.”
“It’s also half the risk,” Izuku countered, his face serious. “The last thing we need is for the public to catch us doing something. A photo, a video… it would be a circus. We’d never recover.”
Katsuki scowled, but he didn’t argue. He saw the logic, even if he hated it. The media dissection, the leering headlines—the mere idea made his skin crawl. “Fine. Our places. Where in our home is a different story.”
A faint, relieved smile touched Izuku’s lips. That was a concession. “Rule two: you have to try to stop always jumping to sex.”
“What the hell is that supposed to mean?”
“It means when you’re feeling… volcanic,” Izuku said, using Katsuki’s own word from his therapy session, “your first instinct can’t always be to push me against a wall. You have to try to talk about it. Even if it’s just three shitty words.”
Katsuki looked away, his neck flushing. The tile crack seemed fascinating. “I’m not good at that.”
“I know.” Izuku’s voice softened. He dared to reach out, his fingertips brushing the back of Katsuki’s clenched hand. “I know you won’t be perfect. I’m not asking for poetry. I’m asking for you to try. To show me you’re fighting the impulse, just a little. That’s the rule: you have to try.”
Silence stretched, filled by the relentless drip of water. Katsuki turned his hand over, letting Izuku’s fingers slide against his palm. It was a small, quiet connection.
“And if I fail?” Katsuki asked, his gaze still averted. The question was raw, stripped of pride.
“Then we deal with it,” Izuku said simply. “As long as you’re trying, and you show a few instances of enough self-control… that’s good enough for now. That’s all I need to see.”
Katsuki finally looked back at him. The storm had calmed into something more like a turbulent, mist-choked sea. He saw the offer for what it was: not a cage, but a lifeline. A structure to keep them from burning their own world down. He gave a single, sharp nod. “Fine. Your rules. But if I’m trying this… talking shit… you can’t just stand there looking at me with those big, fucking tragic eyes. You have to meet me halfway.”
“I will,” Izuku promised, his heart thumping hard against his ribs. This was more than he’d dared hope for.
Katsuki squeezed his hand once, a hard, almost painful pulse, before letting go. The physical space between them returned, but the charge in it had changed. It was no longer purely combustible; it was negotiated, a live wire now housed in deliberate conduit.
“Good.” Katsuki shoved his hands in his pockets, the familiar posture returning, but his shoulders were looser. “Now get your shit. We’re leaving. I’m not having our first attempt at ‘talking’ in a fucking locker room.”
He turned and walked toward the exit, not looking back. Izuku watched him go, a dizzying mix of relief and terror swirling in his gut. He’d done it. He’d named the thing, built a fence around it.
He hurried to his locker, his movements clumsy. When he pushed through the gym’s main doors into the crisp evening air, Katsuki was already there, leaning against the building’s exterior wall. He was staring at the streetlights flickering on.
“So,” Katsuki said, not looking at him as Izuku fell into step beside him. The city sounds of traffic and distant sirens filled the space where Iida’s judgment had been. “Where’s halfway?”
Izuku blinked, thrown. “What?”
“You said you’d meet me halfway.” Katsuki glanced over, his profile sharp in the low light. “I’m trying. So talk. About something that isn’t a mission report or a fucking boundary list.”
Izuku’s mind went blank, then filled with a thousand things. He grasped for the simplest true thing. “I was really embarrassed when Iida saw us.”
Katsuki snorted. “No shit.”
“But I was also… really angry,” Izuku continued, the words finding their shape as he spoke them. “Not at you. At the situation. At having to hide something that doesn’t feel wrong.”
Katsuki was quiet for a full block. His steps matched Izuku’s pace. “It feels wrong to me,” he finally said, the words gritted out. “Not the… being with you. The hiding. It feels like I’m treating you like a secret. Like something to be ashamed of.”
The admission was so stark, so perfectly aligned with Izuku’s own fear, it stole his breath. This was it. This was the trying.
“You’re not,” Izuku said, his voice firm. “You’re protecting us. There’s a difference.”
“Tch.” Katsuki kicked a pebble, watching it skitter into the gutter. “Semantics.”
“It’s not.” Izuku bumped his shoulder against Katsuki’s arm, a tentative nudge. “A secret implies shame. A private life… that’s just ours. No one else’s business.”
Katsuki didn’t pull away from the contact. They walked in silence for another moment, the tension between them slowly transforming into something else, something purposeful and new.
“Your rules suck,” Katsuki stated, the corner of his mouth twitching. “But they’re not completely stupid.”
Izuku laughed, the sound startled out of him. “Thanks, Kacchan.”
“Don’t mention it.” Katsuki looked ahead, toward the neon glow of the district where their apartments waited. “So. Your place or mine? Since we’re following the rules now.”
The question was loaded, but the edge was different. It was an invitation, not a demand. Izuku felt a warm, buoyant hope rise in his chest. “Mine. I have better coffee.”
“Your coffee is swill,” Katsuki retorted, but he was already changing direction, steering them toward Izuku’s street. The night stretched before them, uncertain, but for the first time, it felt like a path they were choosing together, one careful, negotiated step at a time.