Kirishima gaped at him, both of them flushing up to their hair. Katsuki could feel the cool night air steaming on his cheeks, so hot was his humiliation. Fuck, why had he said that!?
Kirishima coughed, looked at him in astonishment, coughed again and bashfully rubbed at the back of his neck.
"I-I guess!? It's a little hard to get used to but I'm working on it." Kirishima flashed a wolfish grin, "finally got you in a spar though, bro."
Katsuki grunted, "don't get fucking used to it. You had the element of surprise. I'll kick your ass next time."
"I won't go down easy!" Kirishima flexed, newly enhanced muscles straining against his loose t-shirt. "These gainz ain't just for show!"
"Keep your fucking voice down you idiot, it's late." Kirishima stuck his tongue out, briefly distracting Katsuki. "The fuck you been doing all this time anyway, chugging protein shakes?"
"I mean, sorta? I had to get this, like, super high calorie high protein stuff sent to me cause the growth spurt was so violent. Something about my body reconstructing itself? Mum said it was important I have enough energy to fully complete my growth or I'd just end up going through it all again." Kirishima grimaced, flexing his hand once more and looking off into the distance. "I really didn't want to have to do that. Once was enough."
"Could have just done that at school." Muttered Katsuki, but something about the look on Kirishima face let him know that this supposed 'growth spurt' wasn't pretty.
Kirishima laughed again, but it was hollow of all humor. "Yeah, no. I don't think that would have been a good idea. The growth spurt was messy enough as it was. Seriously, I was ravenous the whole time, but it was the other stuff that was bad. Really, really bad. I'm glad you didn't have to see it."
Katsuki snorted, "I could have fucking handled it."
"Mmm," mumbled Kirishima, biting his lip, not denying him but not agreeing either.
Katsuki frowned, crossing his arms, "Well, how fucking bad was it then? Is it to do with that other stuff, the chains and shit? Your new form?"
"You mean Red Riot: Predator?"
Katsuki shivered, a vision of Kirishima, a hungry vengeful beast made of earth and teeth, flashing across his mind's eye. The weight of that predatory gaze stirring his blood. Katsuki swallows thickly, sweat breaking out on the back of his neck and his palms. He uncrosses his arms, trying to wipe them covertly on his joggers.
"Yeah, that? Predator shit" his voice cracks.
Kirishima doesn't seem to notice, fiddling with his longer hair. He leans back against his railing, contemplating his words. "So, you know how Aizawa said that in a quirk evolution there's a possibility of gaining a new quirk?"
"Thought he said it would fuse with your old one?"
"Well, yeah. That too, it's kind of both? So my Mums quirk is a animal transformation type, right? Which is where the growth spurt and restructuring of my muscles to make them stronger and stuff comes from. It also gave me a general power and stamina boost to my Hardening-seriously it's so there now, like I don't even have to think about it. I was having trouble not hardening. I've got used to it now, but yeah."
"Where the fuck do the fucking chains come in then? You suddenly decided to use a weapon like Aizawa? I thought you decided against that because you need your hands free for close combat."
"I'm getting there dude. This isn't easy to explain." Kirishima whines, pouting at him.
Katsuki tares his eyes away from the other's lips, huffing. "Fine. Take your time. Not like I'm going anywhere."
Kirishima laughs, humming while he figures out his words. "So while the quirk evolution reinforced my muscles and stuff, I didn't really gain the ability to transform or anything. At least, not properly. There's a few changes if I go all out on my hardening like you saw in training, but I don't turn into an animal or anything."
"Fucking obviously" grumbled Katsuki.
"But" Kirishima continued, acting like the interruption didn't happen. "I did gain a kind of 'awareness' of my body that Mum says is necessary if I were to transform. Something about being a shape-shifter? I guess it's kind of like a secondary quirk, but all it really does is make me aware of my body, down to the finest detail, and allows me to control it a bit. I guess the quirk would be called Full Body Awareness but, that's kind of lame."
Katsuki frowns, worrying his own lip as he thinks. Eventually all he can do is shake his head, glaring at the redhead. "That still doesn't fucking explain anything? What does being aware of your body got to do with going all super beast and levitating chains?"
Kirishima shakes his head, "you don't get it. I'm not explaining it well. It's full awareness of my whole body, down to a cellular level. Not just where my limbs are or how much strength I'm putting into my muscles or stuff. I can feel my blood cells bumping into the walls of my arteries, the oxygen infusing through my lungs, the release of enzymes in my intestines, the electric currents igniting my nerves. All of it. All the time. I can feel it."
Kirishima took a deep breath, turning to look Katsuki in the eye, gaze heavy and serious with meaning. Searching for understanding. "And if I concentrate, I can control it."
Katsuki tried to understand, but it was no use. There was no way he could comprehend what Kirishima was experiencing without going through it himself. It was like trying to picture infinity, the words were there, the concept was understood, but the sheer enormity of the task was too much for the human brain.
"Is that-is that what happened? The day in the infirmary. The day you said it was too much?" He crocked, ghosting a palm along his shoulder, the faintest of scars still visible from Kirishima's claws where he lashed out in pain.
"Yeah. That was the start of it. I started to feel everything, but I couldn't cope with it. My mind hadn't caught up, I couldn't block it out or comprehend the sensations. It got…bad. Really bad." Kirishima took a deep breath, blowing in out in ragged puff of steam, eye tights. "I had seizures at first, lots of them. I think I even fell into a coma at one point, my mind simply gave up. My Mum, well, she got me on sensory deprivation, but it barely helped. It wasn't outside sensations that were tearing me apart, it was the ones within."
"Couldn't you-didn't she do something? Something to fucking help?" Katsuki gripped the railing, palms going white with the strength of his grip.
"There wasn't anything to do." Kirishima ran a hand through his mane of hair, voice tight with distress and remembered pain. "She told me, at the beginning, when I was still lucid, that I had three options. One, to go through with the transformation and break through with my own will. Two, to succumb to the pain and be driven to madness. Or three…"
Katsuki waited, heart pounding, breathing hard. "Or three what? Fucking what Kirishima?"
Kirishima swallowed, voice tight. "Three, she could end my suffering then and there, kill me quick."
Katsuki growled, something snapping in his chest. Surging forward he reached over to pull Kirishima towards him, smacking their foreheads together with a thump. He gritted his teeth through the pain, blazing eyes staring into teary red crimson orbs. Breath ragged Katsuki squeezed those wide shoulders, thick calloused palms finding the back of the redhead's neck. For a moment he couldn't speak, so swept up in fury, simply breathing in Kirishima's air. Feeling his hitched breaths wash warm and alive across his face.
"Like hell," Katsuki growled at last. "End your fucking pain? What the fuck?! She should know you're a fucking badass, that your strong. Manly. You don't back down and you don't fucking break!"
Large palms wound around Katsuki's chest, squeezing tightly. Kirishima eyes fluttered, a slow smile stretching across his lips.
"No regrets" he whispered. Kirishima pressed closer still, eyes crinkling, gentle and warm. "I-I missed you Katsuki. I really missed you."
Katsuki shivered, heart pounding and mouth dry, searching for something to say in return. Maybe, I missed you too Shitty Hair. Or, I know that idiot. Or even, if you missed me then why th hell didn't you reply to my texts asshole!?
But none of that passed his lips. Instead, his palms warmed, gripping the redheads solid form more tightly, squeezing. Trying to convey everything he couldn't say through that touch, to make Kirishima understand.
Kirishima understood, Kirishima always understood. That smile grew, sharp teeth flashing, radiating happiness and contentment. Katsuki felt his heart skip a beat, warmth breaking out in his chest, and knew he was fucking done for.
Because Kirishima's smile might have a new set of teeth but it was the same as before. The same joy inducing dizzy stretch of lip, the same warmth, the same boyish optimism and gentle pride. How the hell was Katsuki not meant to fall in love with him?
He pulled away, heart pounding slow and heavy with want. His whole body sinking with warmth. Peace settled into his bones, long lost in the months Kirishima had been away. Kirishima let him go reluctantly, hands still reaching. He pouted, shoulders dropping.
"Are you coming in or not? It's fucking late and I've still got shit to ask you?" Katsuki shot him a look over his shoulder, parting his curtains to return to the gloom of his room. It was cool from the night air and he quickly got under the covers.
Kirishima jumps the balconies, landing with a heavy thump, and rattling the latch as he shut the window behind him. Katsuki lifted up a corner of the covers. The feeling in his chest making him bold.
"Get in Shitty Hair. It's fucking cold as balls in here."
"I'm not sure I'll fit."
"You're not that fucking big, you'll fit fucking fine. Just get in, I'm not asking again."
Kirishima scrambled under the covers, his weight dipping the mattress so that Katsuki found himself rolling into his side. As always Kirishima ran hot, like a furnace existed in his chest. Katsuki let himself absorb the warmth, wrapping himself around the redhead until he was half lying on Kirishima's chest. He could feel the boy's heart pounding away, the rise and fall of his chest as the redhead's breath caught. It had Katsuki's own heart pounding in return, trying to match that fast-paced rhythm.
Slowly, strong arms wrapped around Katsuki, a touch of disbelief colouring Kirishima's voice. "Is this okay?"
Katsuki closed his eyes, twining their legs together and pressing his icy feet to one strong calf. Kirishima pinched his side in retaliation. "'Course it fucking is. Stop stressing Eijiro. I'm tired."
Eijiro squeezed him, the air under the covers heating with their combined body heat. Slowly, Katsuki relaxed into that chest fully, eyes starting to drop and mind becoming sluggish. Eijiro ran a hand through his hair. Strong, sure fingers massaging his scalp pleasantly.
"You still didn't explain the chains," Katsuki rumbled, eyes closing.
"They're liquid metal mixed with my blood. I can feel each cell and control it through my quirk. Hardening causes changes in the structure, allows me to push and pull on them. Still clumsy though."
Katsuki hummed, the rumble of Eijiro's voice washing over him pleasantly. After a moment, just as Katsuki was really dropping into sleep, the redhead whispered his name, letting out a long sigh.
Eijiro dipped his chin into the space between Katsuki's collarbones, rubbing his cheek their gently, scenting him thoroughly. Lips brushed against his neck and Katsuki couldn't help his breath hitching. Eijiro gravitated to his pulse point, leaving a lingering kiss.
"Katsuki," Eijiro whispers, half in question, half in prayer. One carmine eye cuts open, catching the others wondering gaze. His pulse thunders.
Katsuki reaches out, running an explosive palm from the tip of one horn, through that burning mane, across a strong neck and up to a soft cheek. He tips Eijiro's head closer, giving the other only the smallest of moments through which to pull back. Eijiro squeezed his waist, one finger dragging a burning brand across the skin of his lower back.
Katsuki presses their lips firmly together, feeling the fleeting press of those dangerous teeth. Eijiro makes a surprised wanting noise, rolling him closer.
The kiss is a hesitant exploration, a shy confession, but Katsuki can feel the burn starting in his veins. The flash of heat across his skin. The promise of passion and desire.
But its late and this is new, fragile, not to be rushed. So he draws back.
"Katsuki, I-I," Eijiro whimpers into the warm air between them. Katsuki silences him with another short press of lips. And then one more, because he wants to.
"Tomorrow" he whispers, "tell me tomorrow."
But in the morning, waking up to a smiling happy faced Eijiro in his bed, whole and well and back where he belongs, Katsuki's the one who says it first.