The first time Todoroki went into subspace with Bakugou, they were training, of all things, and in the literal heat of battle Bakugou had somehow managed to pin him to the ground, face-down, and was straddling him, leaning over him with the full weight of his body. The left side of Todoroki's uniform was in tatters from the use of his quirk, and as he struggled to get free of Bakugou's hold on him, a few beads of sweat fell from the explosive hero's forehead onto his bare upper back and instantly ignited upon contact with his superheated skin.
His body jolted upwards and then he was in a daze, his desire to fight back totally gone.
The next thing he knew he had been flipped onto his back and most of Class 1-A was looking down at him with concern etched on their faces.
Bakugou squatted next to him, looking at him curiously with furrowed brows. “What, so you turn stupid like Pikachu if your body gets too hot or something, IcyHot?”
Todoroki sat up and shook his head. In the moment he was just confused. “I don't know…” he had said. “Not sure.”
But later that night in his dorm room, when he was thinking over the past day, he'd realized what it was. And he wanted more. And he wasn't ashamed of it.
So he knocked on Bakugou's door.
“How many fucking times do I have to tell you it's unlocked, Deku, you don't have to--” He stopped when he realized it was Todoroki standing in front of him. “What do you want?”
“Overusing my quirk doesn't make me go stupid like it does with Kaminari.”
“Okay…? Then explain what happened today.”
Todoroki strode across Bakugou's room and sat on the edge of his bed. Bakugou sat up and put the book he was reading off to the side.
“It's called subspace.”
“It's called /what now/?”
And thus began an awkward BDSM primer.
“What the actual fuck, IcyHot?” Bakugou said when he was done explaining. “Why tell me this shit?”
“Because I want to do it again.”
“You wanna-- you want me to…?”
“Listen. If this were to ever happen during training -- or during an actual fight -- again, I need someone who understands what's going on. Who knows how to handle it. You can understand why I don't want to go to any of the teachers, right?”
Bakugou nodded. “Yeah, I guess.”
“And besides, I like it.”
Bakugou swallowed. “Okay, fine. But we're not starting with my quirk. We'll start with candles or some shit. Also, we can't do it here. Don't wanna burn the dorms down. We'll sneak out and go to Gym Gamma, since it's all cement.”
Todoroki let slip a small smile. Bakugou was already thinking about the small details. He was going to be good at this.
The second time Todoroki went into subspace with Bakugou, it was in the middle of the night on a school night, spread out on a fireproof sleeping bag (“I told Hatsume I needed something like it for overnight training,” Bakugou said, shrugging) on the chilly concrete floor of Gym Gamma. Bakugou had also brought a fleece All Might blanket with him, but it quickly became a fire hazard, and besides, All Might's face staring up at them in this situation was pretty weird.
“So you just want me to tell you what to do, and you do it, right?”
Todoroki nodded. “And check in on me.”
“Obviously. Do you, uh, want me to tell you what I'm planning on doing?”
“No. It's best if I'm not expecting it.”
“Kay. Gimme your hand.”
Todoroki held his hand out. Bakugou took it in his own, lacing their fingers together. “If I do this, it means squeeze if you're okay. If you don't squeeze, I'll stop what I'm doing. Yeah?”
Todoroki didn't say anything, just squeezed Bakugou's hand.
The blond snorted, pulled his hand back, and ran it through his hair. “Take off your shirt and then sit down, back facing me.”
Todoroki did what he was told, shivering a little bit at the sudden exposure of his chest to the cool night air. He sat down on the ground, and then Bakugou was lowering himself to the ground and scooting behind him. He spread his legs out long, almost as if to surround Todoroki on multiple sides. He was already feeling a little warm and fuzzy at the idea of Bakugou folding himself around him like this.
“I'll be right here the whole time,” Bakugou said, his voice husky in Todoroki's ear. And then he was dragging his hands down Todoroki's back, with just enough force to leave fading red lines behind. Todoroki sighed and leaned into it.
It felt soothing, honestly, not really painful at all.
“You can do better than that, Bakugou.”
“Shut up, Half and Half, I'm not gonna jump right into quirkplay. Just relax and let me do my fuckin’ thing.”
“Fine.” Todoroki cleared his throat. “But if you can't square up I'll just have to ask Midoriya to help me out instead next time.”
That did the trick.
“Can shitty Deku do this?” Bakugou growled, fisting one hand in his hair and resting another on the small of his back. Before Todoroki could respond, heat was building where Bakugou’s hand rested on his back, and he gasped, his eyes watering at the burning sensation. And then it was gone. Todoroki whined and sought Bakugou’s eyes with his own.
“Do it again,” he said, just the slightest tremble in his voice betraying his unraveling calm.
“Tch. Don’t get ahead of yourself.” Bakugou pulled up on the waistband of Todoroki’s pants. “Take these off.”
Bakugou watched him as he stripped, silent, almost glaring, and Todoroki blushed. He felt a sudden urge to curl in on himself. Bakugou was still fully dressed, well, in pajamas, but they were still clothes, and he didn’t seem like he would be taking them off anytime soon.
Why was he trusting Bakugou with this again? Out of everyone in their class, why had he decided to go to probably the most dangerous person he knew?
Maybe, he thought, as Bakugou moved him onto his hands and knees, that was exactly why he had gone to Bakugou for this.
He suddenly realized that Bakugou was holding his hand. Todoroki glanced back and Bakugou was looking at him, his eyes expectant but his expression calm. He squeezed the blond’s hand and Bakugou broke into a small, smug smile.
“Good,” he said, leaning over Todoroki and running his hands softly down his back. “You know, at first when you suggested this to me I thought you were crazy. I was like, whatever, I’ll do the guy a favor, we’re all into weird shit. But now--” He started running his fingers in a tapping motion down Todoroki’s back, and Todoroki realized that they were slowly getting hotter, teasing him with small stings that lasted fractions of a second. “--Seeing you like this, I’m thinkin’ maybe there’s something to it.” He leaned down and whispered, hot lips brushing against Todoroki’s ear. “I think I’m gonna get off on this too, IcyHot.”
And that was all it took for Todoroki to fall into that fuzzy headspace he’d been searching for. He let out a moan and heard Bakugou make a satisfied noise behind him.
“I haven’t really even done anything yet, Todoroki,” he sneered. “Are you really that much of a slut for this kinda shit?”
Todoroki felt his arms wobble as the insult made him blush. “Maybe,” he whispered, afraid of what reaction not answering might bring.
Suddenly, Bakugou’s teasing touches were gone, and he had one hand fisted in Todoroki’s hair instead, yanking his neck back.
“Gimme a flame,” he spat.
“Just do it!” Bakugou said, tugging a little more forcefully at Todoroki’s hair.
He lit up his left side, and Bakugou leaned back, rummaging through his bag for a moment.
“Oh,” Todoroki said as Bakugou leaned back over him. He could feel Bakugou’s cock through his pajama pants where it was pressed up against his ass. “You weren’t kidding about the candles.”
“Shut the fuck up IcyHot, of course I wasn’t kidding about the candles.” He placed one hand over Todoroki’s right hand, not lacing their fingers together just yet, but poised to. “Okay, starting,” he said, and dipped the long, tapered candle into the flames on Todoroki’s left side. Once the candle was lit, Todoroki extinguished them, and waited, stock-still, his mind buzzing.
“Bakugou, what’re you waiting for?” Todoroki whined. “Come on! I can see it dripping on the ground.”
Todoroki let out an annoyed groan. “/Please/, Bakugou,” he said, rolling his eyes.
Bakugou hummed to himself. “Y’know, I’m actually not sure how I feel about you calling me Bakugou anymore. Not in situations like this, at least.”
He moved the candle so that it was hovering over Todoroki’s back, and droplets of wax began falling onto his shoulder blade.
Todoroki flinched and gasped out a surprised “ah!”
It still wasn’t the exact feeling he was searching for -- he wanted lingering, deep, searing pain -- but this was a nice warmup. He felt himself slipping slowly deeper into the desired headspace, relaxed and focused only on the steady drip-drip sensation of the soft heat on his back. “If not-- not Bakugou--- then-- what?” he panted, his voice an octave higher than it would normally be.
Bakugou held the candle out to the side and leaned over Todoroki, grinding into him as he laced their fingers together and growled in his ear. “I was thinking sir.”
Todoroki squeezed his hand the hardest he had all night and whimpered. “Yes-- yes, sir.”
Bakugou let out a soft, animalistic noise and pulled the shell of Todoroki’s ear in between his teeth before drawing back again. “You know what?” he said after a moment. “Fuck this candle.”
Out of the corner of his eye, Todoroki saw the candle fly across the Gym Gamma grounds.
The next moment, Bakugou’s hands were on Todoroki’s ass, kneading his flesh, his thumbs digging into the back of his hips. They felt warm.
Not hot yet, but Todoroki hoped, with a surge of anticipation, that they were getting there.
“Whaddaya think I should call you, hmmm?” Bakugou said absentmindedly.
“Wh-- whatever, you want, sir,” Todoroki mumbled.
“Whatever I want? Ha.” Todoroki could hear the derision in Bakugou’s voice. It was making his knees buckle together. “What about my pretty little slut?” Bakugou suddenly landed a sharp slap to Todoroki’s ass and he yelped, bucking forward.
Bakugou reached down and wrapped his arms around Todoroki’s torso, holding him up.
“If you want you can touch yourself during the finale, okay, slut?” he said, and Todoroki nodded, too out of his wits to string together words anymore.
“I brought a little stockpile of my sweat just for you.” Bakugou reached back into his bag with one hand, pulling out a dropper. “Okay,” he said, his breathing heavy as he started grinding his still-clothed hips forward into Todoroki’s ass. “Get nice and hot for me.”
Todoroki heated up his left side, trying his best to not overdo it even though he was really, really ready for this to happen. He heard the first “pop” of an explosion as Bakugou let loose a drop of sweat onto Todoroki’s skin, and then felt it -- sharp, almost too painful to describe. Todoroki’s body seized up in shock and then went limp as the feeling dissipated, and then tensed up again as another drop hit him -- pain, relief, tension, release, over and over in a dizzying cycle until his body was loose and shaking and he was possibly crying but he couldn’t quite tell and -- oh, was that Bakugou’s hand on his? -- he squeezed as hard as possible and it kept on going -- drop after drop, searing through his flesh, branding him, he found himself hoping, God, he was fucked up--
The burning sensations stopped as he felt a different type of pain and realized that Bakugo was biting into his shoulder, and something hot and damp soaked through Bakugou’s pants and into the cleft of his ass.
“Fuck,” he heard Bakugou pant behind him as he stopped biting him and rested his chin on his shoulder instead. “Fuck,” he repeated. “Why weren’t you touching yourself?” Bakugou asked once he’d caught his breath.
Still in a faraway headspace, Todoroki simply mumbled “too much.”
“--Can I help?” Bakugou asked, his voice sounding just the tiniest bit hesitant.
As Bakugou wrapped a hand around Todoroki’s length, the front of his body pressed up against Todoroki’s back, and the sweat built up there from Bakugou’s exertion ignited all at once along Todoroki’s left side.
Todoroki heard himself scream more than he actually screamed himself, and his vision blacked out for the briefest moment until all of his attention was drawn to his core, suddenly at the apex of pleasure, as he let out a surprised shout and came onto the cement below him.
His orgasm was a little too sudden and a little too short, but he hadn’t come here chasing an orgasm, he’d come here chasing a state of mind, and he clung to that headspace as he collapsed backwards into Bakugou and let his classmate curl around him on top of the ridiculously -- and helpfully -- tactical sleeping bag Bakugou had brought for the occasion.
“IcyHot, we can’t fall asleep here, c’mon,” he heard, he wasn’t sure how much later, as Bakugou gently nudged him into consciousness.
Todoroki whined and then sat up. His back felt tender, but otherwise, he felt like he’d just taken a really fabulous nap. He stretched and then stood up, picking up the sleeping bag.
“You, uh, need anything else?” Bakugou asked. He was holding the fleece All Might blanket bunched up awkwardly over his crotch area.
“Nuh-uh,” Todoroki said. “I think sleep might be all I need as far as aftercare goes. Thanks for putting my clothes back on, though.” He swallowed. “How’s my back look?”
Bakugou shrugged. “Fine. Just some red marks. I guess your quirk makes it hard to get actually seriously burned.”
As they snuck back across campus towards their dorms, Todoroki was overcome with a fit of uncharacteristic giggles.
“What the fuck is wrong with you, IcyHot?” Bakugou whispered. “We’re gonna get fucking caught if you don’t shut up!”
The childlike euphoria Todoroki was feeling was indescribable, and it was undoubtedly an effect of their play.
But he didn’t have the words to explain that to Bakugou, and all he could think of to say instead, as he leaned into his classmate, laughing, was, “I can’t believe I made Bakugou Katsuki jizz in his fucking pants.”