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It had been three days since they had been hit with the quirk, and Kirishima was beginning to discover that maybe he wasn’t exactly as patient as he prided himself to be.
Being stuck in Bakugou’s body was extremely disorienting. Seeing his own face scowling and hearing his own voice angry from a constant third-party perspective was something he just couldn’t get used to.
He was in a shorter body now, too, considering how over the years Kirishima had eventually grown to be taller than Bakugou. It wasn’t a huge change, a few inches at most, but there was a strange sensation that came with being a height he hadn’t been since a year ago that made him constantly feel like he was falling.
According to the quirk records of the villain that got them, which included every other instance they had been involved in, the quirk should have reverted after two days at the very most.
Unluckily for Kirishima and Bakugou though, it was boosted by a drug at the time they were hit, so the effects would last for, potentially, much longer. It was a panic administration when the villain was cornered, they had taken the dose merely a minute before hitting the two, so it was at the peak of its effect. All they could do was wait and take daily checkups with Recovery Girl to check the quirk levels in their bodies to hopefully come to a prediction of when it would finally be over.
Kirishima was honestly quite happy about it for the first few hours. Whenever he’d look in the mirror, he’d see Bakugou, so whatever expression he pulled showed on the blond’s face, too.
Holy fuck, did he spend a long time exploring that.
Like anyone with a crush, he had imagined the many different ways Bakugou could react to finding out his feelings. Though Kirishima felt somewhat weird about it considering they were both young adult men and not middle school girls fawning over celebrities, passing up this chance would be a huge regret of his. So he didn’t.
He stared into the mirror and pulled almost every face imaginable. Shy smiles, confident grins, and even attempts at replicating Bakugou’s infamous curls of lip.
Kirishima didn’t know what came over him when he ran his fingers back through blond hair, that was much fluffier than it looked, and scraped the unfamiliar flat teeth over a plump and blushing bottom lip, while the red eyes of a hue more intense than his own stared back at him with some kind of promise.
For a moment he completely forgot that he was the one in control of the expressions Bakugou’s face was pulling and the sultry look he just accidentally gave caused a familiar stir of arousal to burn in his stomach. Or, Bakugou’s stomach, technically?
It caused Kirishima to freak out pretty quickly because oh shit I’m getting a hard-on in Bakugou’s body and the explicit thought of what was happening only made it all the worse.
Over the next couple of days, Kirishima had done everything necessary to avoid seeing, touching, or even so much as thinking about Bakugou’s dick, ass, chest, thighs, and honestly any part of his body literally at all.
Awkwardly sitting down on the toilet when pissing, eyes scrunched shut when slowly changing, he hadn’t even showered since being in Bakugou’s body.
As a healthy young man with a very clear and picturesque imagination, he rarely went longer than a day without jacking off and when he did, something just felt not quite right with his body. Whether Bakugou himself was interested in sex at all wasn’t something they’d ever discussed but Kirishima seemed to have carried his sex drive into this body and not knowing how long he would have to go without releasing it was painful to even think about.
The worst of it all is that Bakugou would be mad at him about this, pissed off that he wasn’t taking care of his body correctly, but Kirishima knew for an absolute fact that running his hands all over every crevice of Bakugou’s wet and perfect body, no matter the context, would end in white.
He lasted another day.
—
Being somewhat close to graduation, the majority of school time was spent purely on physical training, which Kirishima and Bakugou couldn’t partake in due to the unfamiliarity of handling each other’s quirks. However, they could still spend that time doing written studying together, which is what they were assigned to do by Aizawa.
When changing in the morning, getting ready for school, Kirishima had his eyes shut tight like he had every time previous. He tried to step into the pants one leg at a time, but his coordination was slightly off and instead of his second foot going cleanly through the hole, he tripped over the bottom seem of the rise, causing him to open his eyes wide in panic as he fell to the left.
He managed to catch himself rather easily due to his trained reflexes so he didn’t fall on Bakugou’s face, but at the perfect angle and position that he was staring directly into the body length mirror on his hands and knees.
Though what he was seeing wasn't himself on his hands and knees, it was Bakugou. A heavy breath left him as he willed himself not to look down to his chest, but his resolve was surprisingly weak.
In reality, he looked at Bakugou’s chest often when they were in their own bodies anyway, so really, looking now wasn’t anything different. He could admire his best friend’s training results and muscles! Admire he did. He shuffled to sit cross-legged in front of the mirror and stripped off the pants that were hanging onto the one foot then let his eyes wander.
He barely took note of the fact he was sat in nothing but underwear, or that he had been so strict with what he allowed himself to indulge in with Bakugou’s body since the start of the quirk yet suddenly, after an accidental glance at full pecs and perky nipples, he was in a trance and most of that resistance was as at a constant rate of decline.
It could’ve been minutes or hours he was sat there for, the flow of time rendering itself null as Kirishima just sat and stared. Admiring the dip of his collar bones, the curve of his hips, the tightness of his abs, the fullness of his pecs... the prominent bulge that was now sat snug underneath the fabric of black, baggy underwear... fuck.
There was no avoiding it anymore. Day three of who knows how many into this experience and the dick he had been ignoring in every way possible was as hard as his own quirk after a few minutes of looking in the mirror. It would surely become a detriment to his everyday life soon enough, the risk of popping a boner around the actual Bakugou (albeit, in his body,) was only increasing.
He had to take care of it now, tend to Bakugou’s body in the way it was screaming to be taken care of.
Moving to his knees, he pulled the underwear down in a quick motion, spreading his legs slowly to get a good view of everything in the mirror.
Bakugou’s dick sprang up as soon as the fabric had left it, bobbing lightly in the cold air, and Kirishima had to bite down on his lip to resist from moaning too loud. He was thankful for his now flat teeth or the marks left there would have been hard to explain away.
He couldn’t help but stare for a few long seconds. It was pinker and lighter in weight than Kirishima’s own and it looked to be smaller though it was kind of hard to tell in ratio, but it sure was a pretty thing indeed. Neat and wet, pre already shined on the tip and threatened to spill.
Wrapping the head in a loose fist, Kirishima slowly dragged his thumb over the tip with a shudder, collecting the bead of precum there and then brought his thumb to his mouth to taste it. A small moan left him as the salty liquid was rubbed on his tongue and it ignited something primal within him.
It was quick then that he spit on his hand and wrapped it tight around the head, not wasting any time as he set a pace dragging up and down roughly, the slight slide from the saliva making the process smoother.
Kirishima had spent many years figuring out and mastering what things his body liked, which places felt good to press and focus on, so when those same things didn’t have the same affect, he was somewhat at a loss for a short minute.
Bakugou’s dick was sensitive in different places, in which Kirishima accidentally discovered with a small bit of experimenting. Rubbing under and squeezing the head and putting added pressure on the prominent vein running down the side had caused his breath to catch and a needy groan to slip out.
It was then he noticed where his vision had been focussed the entire time. He was still on his knees and looking into the mirror, specifically at Bakugou’s dick, which was amazing, but he had Bakugou’s entire body to appreciate and he didn’t want to leave a single inch of skin unappreciated.
He continued the ministrations on Bakugou’s dick as he moved to look higher, to make eye contact with himself and another, more coherent moan sounded. Watching Bakugou’s body like he was just watching the man himself put on a show was almost as stimulating as the hand he had working quickly on the dick that was slowly turning redder and getting wetter with the slippery fluid it created.
Bakugou’s eyes were watering, red and pink blotches of blush travelling from his cheeks all the way down to the top of his chest, accentuating the fullness of his pecs even more.
Not a single thought had time to go through his head before he slid his free hand up the hardness of Bakugou’s abs, making it’s way towards his pecs, of which he took a firm handful of and began to fondle.
His hips began to involuntarily thrust into his hand, the orgasm building quickly in his stomach with a warm hand mercilessly playing with his tits.
Not a second went by without some kind of incoherent moan or gasp, the pace of the hand on Bakugou’s dick increasing to push him over the edge, but once looking into Bakugou’s eyes again, just when he was about to cum, he willed himself to pull both hands away and lean back.
In reality, Kirishima had no idea how long he would have to enjoy this. He’d already crossed the barrier of doing it once, and there was absolutely no way he could resist again after this, and there had been three whole days of missed opportunities. If he was never going to get to see this in any other situation anyway, he was going to milk it for all he could until the sight of Bakugou falling apart was etched onto the backs of his eyelids.
Kneeling had become quite taxing, his calves aching with the retired weight on them, so Kirishima sat back on his ass and slowly spread his legs to either side of the mirror.
Bakugou’s cock was angry now, red and swollen as it begged for release, and at the slow reveal of his twitching asshole as his legs spread, Kirishima quickly realised that he absolutely would not be able to hold on for as long as he wanted to.
So he wrapped a hand around the length again, eyes now dropped towards the hairless pucker exposed between Bakugou’s asscheeks.
It would be so tight inside, would clamp down on his tongue and fingers and dick, would suck him in and beg for a hot load, not letting go until completely satisfied with everything Kirishima could give him. Fuck, he wanted to touch around and inside it, wanted to bury three fingers to the very last knuckle and watch Bakugou squirm in a desperate attempt to ride them while asking ever so nicely for something thicker and bigger.
The mere thoughts of that had Kirishima dangerously close to the edge already and even though he hadn’t laid a finger even close to Bakugou’s twitching hole yet, there was no way he would ever last long enough to reach it.
“Fuck, just like that, Eijirou.” He moaned out once suddenly looking back to Bakugou’s face, wanting to see the look on his face as he came hard.
As strange as it was to moan his own name, he heard it as Bakugou’s voice and saw it as coming from Bakugou’s mouth and in the bliss of the orgasm it triggered, the disconnect between himself and the body he was in had reached a point he couldn’t distinguish.
The cum had shot up, trailing all the way up to the valley between Bakugou’s pecs. He couldn’t help but think about licking it clean, burying his face between the plush mounds and biting down over the area of them, over the darkened areolas, but that was a fantasy he unfortunately couldn’t fulfil while in this predicament. So likely never would
Kirishima continued to tightly stroke, coaxing out every drop of cum and milking Bakugou’s dick for all it had to offer.
However, his eyes were still glued to the mirror, and seeing Bakugou’s stomach and chest covered in cum, seeing his blushing skin, messed up hair and spread legs, smelling the permeating sweetness of his sweat, it all made his head spin and the familiar fire of arousal begin to stir within him once more. Shit, he had a class to be going to!
It was going to be a long few days until they switched back.
—
The eventual switch back (which took a whole week to occur) was a strange experience. It happened while they were both awake, unlike when they were hit with it, though it triggered a harsh few-second blackout for them to both shoot back to complete control and consciousness inside the familiarities of their own bodies.
Kirishima was confused, even panicked a little when he shot up like he’d been electrocuted, only to realize that he was just laying on his own bed in his own room.
Though, not everything with his body was exactly how he had left it.
He was panting, almost desperately, which could have been a side effect of the switch if that was the only thing off.
However, he was also naked and uncovered. It was nearing dinner and not particularly cold, so what was the need for Bakugou to...?
It took Kirishima a few seconds to realise and believe, but with the way his dick was half hard and slowly softening and a decent amount of fresh cum was smeared over his abs, it seemed that Bakugou had just as much of a good time as he did.