Chapter Text
Katsuki woke up slowly, already sure something was off, but not quite sure what it could be. Taking stock of what he could, his sleep-addled brain notes that his pillow is a little softer than it should be. He'd always preferred a stiffer pillow to actually give his neck some support, so it's odd to feel his head sinking right into the cushion. Another thing that's odd is how warm he is. Sure he tends to run a bit hotter than most people, but it felt like he was laying next to a damn heater! Speaking of a heater… he felt arms tighten around his waist- what the fuck. And suddenly he's wide awake, kicking and swinging at whatever idiot had the balls to touch him while he was sleeping.
But getting a better look at the person laying next to him, he sees the confused and startled face of his father. Again, what. The. FUCK.
Not even bothering to look back at the old man, even as he cautiously trailed behind, Katsuki storms out of what was apparently his parents' bedroom and stomps down the hall to his own. Throwing the door open his assumptions are unfortunately confirmed when he's faced with his own body jerking up at the sudden noise.
"What the fuck is with all the racket!? What's got your panties in a twist this early in the morning, Katsu-" His own voice trails off as his hag of a mother finally notices something's amiss. "You better have a good explanation to why I'm looking at my own fucking body!"
Katsuki huffs angrily, of course the hag would blame him before even knowing what was going on. "You tell me! Because I'd bet it's the same reason I'm looking at mine!" Fortunately, before she could respond, Masaru decides to force his way between them with his hands up in a placating manner.
"Why don't we all calm down, okay? Somehow you two must have swapped bodies, but we don't know how, correct?" He pauses until they both nod, scowling. "We can just go to the police and see if there are any known quirks in the database with this ability."
It's a bit of a hassle getting ready, both mother and son having to get ready in unfamiliar rooms with unfamiliar bodies, but Masaru is quietly lending a supportive hand (begging them to stop yelling at each other from across the house to find each garment they needed). And getting to the station was another test of the man's seemingly endless patience for his family.
And when they finally got there Katsuki wasn't the least bit surprised that the police were useless. It was a tense ride home, Masaru obviously driving with the hag in the passenger seat and Katsuki in the back. Apparently there were two possible quirks that could swap peoples' bodies that they knew of. One would wear off 24 hours after the swap occurred, so they'd wake up in their own bodies. The other… had some weird ass requirements about some type of deepened connection or something? Katsuki kind of stopped listening when he realized he didn't actually give a shit about that sappy crap. They'd just have to hope that it would only last a day because Katsuki would be damned if his perfect attendance was ruined by some loser with shitty quirk control. A lame ass trip to the aquarium was not worth this bullshit.
Masaru had tried to strike up conversation a couple of times, being optimistic about their situation. Assuring them it was likely the easier quirk, but even if it weren't this could be good for them! They just needed to sit down and understand each other a little better, maybe show some compassion so they could go back to normal. When that only earned him disbelieving scoffs from the irritable passengers he kept quiet for the rest of the drive and turned on the radio.
The rest of the day mostly consisted of the body-swapped ignoring each other and Masaru fluttering around the house nervously. Katsuki would feel a little bad to put his dad so on edge if he weren't so fucking livid. He ended up sleeping on the couch that night, feeling too awkward to sleep next to his dad again and not wanting his mom to wake up in his room. Mitsuki eventually agreed to take the guest room because it'd be awkward for him wake up next to his dad in his own body… just the thought made him blush and feel the urge to hide.
The next morning when Katsuki woke up, he was once again in his mother's body. He felt resigned to his fate, not even able to gather the energy to get pissed off about it. That was until he ran into his own body, possessed by his mother on his way to the bathroom, and they immediately started quietly bickering.
The two calm down eventually and fall into a familiar rhythm, preparing a simple breakfast and putting the coffee on so they didn't have to go through the day uncaffeinated. It was only once they were almost done with the tasks they started talking again, trying to decide how to proceed now the quirk was still active.
"So we just go about our day and pretend to be each other?" Mitsuki asks pointedly, clearly not on board with the half baked plan.
But, Katsuki isn't having it, he's got his own priorities. "Look. I've had perfect attendance since I was six, I'm not letting some shitty quirk, or some hag fuck that up for me." He placed a hand on his hip with a sharp look, ignoring just how much he looked like his mother in such a position (especially now that he was literally in her body).
It would seem, he was not the only one that thought so, as when entering the kitchen where his wife and son were arguing, Masaru placed a sweet kiss to, what he thought was, Mitsuki's cheek. The action made the other two pause, but he was still too sleepy to notice the change, instead making his way to the coffee maker to properly wake up.
"I'm glad that you two seem to be back to normal, though I'll admit I had sort of hoped you'd get along a bit better when the quirk wore off." His father joked kindly, and just like that… after feeling the soft press of his dad's lips against him, Katsuki's priorities had changed.
He sauntered his way up to his father and placed a gentle hand to his shoulder before returning the kiss and smiling in that soft way his mom reserved for Masaru alone. "If only our brat could've suddenly developed some manners." He tsked, hating that he had to insult himself, but needing to play the part.
Mitsuki, who had been too stunned to respond at first was clearly about to bark out some indignant denial about the quirk still being activated so Katsuki slapped the back of her head, just as she'd done to him countless times. "Don't even try to deny it." He spit with warning only she would truly understand, ignoring the way the hands of his actual body started to spark.
Masaru disappeared back into their room once he'd finished his coffee, humming a cheerful tune, entirely unaware of the storm that was about to come crashing down on the household. "What the fuck are you playing at?" Mitsuki spat when her husband was finally out of earshot.
"The fuck do you mean? We agreed to act normal." Katsuki smirked, obviously bullshitting, but oh how he enjoyed seeing the way his own face screwed up and flushed with anger.
"Yeah! By going to school for you and having you work from home! Not lying to my husband!" Despite her anger, Mitsuki was still keeping her shout relatively quiet, not alerting Masaru about the issue.
Katsuki just shrugged uncaring, "if we want this stupid quirk to wear off we have to learn to understand each other and 'deepen our connections', or whatever the fuck those cops were on about. I'm just trying to make it easier for us."
Mitsuki could tell he was lying, knew that he had something planned, but she wanted this quirk gone more than she cared about scolding him right now. "Fine. But I swear, if you do something stupid with my body I'll make you regret it."
Unfortunately Katsuki couldn't be so easily threatened, so he nodded towards the front door and smirked. "Better get leaving or you'll be late to school, brat." A line he'd heard countless times before, one he was far too smug about repeating now.
It visibly takes everything in Mitsuki's power to not physically attack her son, knowing it would only hurt her own body in the end. She knew he'd do something they'd both regret, but there wasn't anything to do about it until the quirk wore off… What a shit show.
Once his mom was out the door, Katsuki let the unhinged grin he'd been holding back finally split his face. He can't believe the situation that had just fallen into his lap! Maybe he wouldn't kill whoever used their quirk on him if he could get his way. All he had to do was play the part for long enough to get his dad's guard down… then- fuck. He could finally have his dad all to himself.
Normally his parents would work in person, but from time to time they would use the at-home office and just take care of the behind-the-scenes bullshit. And since Katsuki had the best luck of all time… it just so happened that today Mitsuki had assured him that there would be no reason for him to actually go into the office to take care of the paperwork she had to get done. Now all he had to do was convince his dad that he could stay home as well… and rush through their work so they could actually make use of the empty house.
His dad was such a pushover he can't imagine it being all that hard… but what if he actually succeeded? He's never had sex before… let alone in the body of a fucking hag! Would this count as losing his virginity if he was in someone else's body? … whatever, not like he hasn't been fantasizing about taking his dad's cock as long as he could remember.
"Is everything alright, Darling? You've been staring at the door pretty intently. Was it something Katsuki said? You know, if he went too far I'm sure I could have a talk with him…" Ah, speak of the devil.
Katsuki just huffs and smooths out his expression, "You'd talk to him?" He barks out a laugh, softer, more teasing than actually mean. "No… it wasn't him. I was just thinking about something."
Masaru sighs, relieved that they hadn't started fighting when he left the room. "Is there anything I can help you with?" His dad walked over and started rubbing gently at his shoulders and it felt fucking heavenly. Wow, his dad's hands were deceptively strong… and big.
"I was just thinking… Work is pretty light today right? And with Katsuki at school, we could have the house to ourselves for the day." Katsuki chances a look at his dad's expression, trying to keep his tone calm and conversational. Not at all the antsy desperation he feels.
Masaru hums at the idea. "I suppose we don't have any reason to go in today, our team already knows what to prepare and all the paperwork is digital these days." Then he looks at Katsuki more intently, his eyes alight with an emotion he'd never seen from his dad before. Holy shit… did he just feel his mom's cunt throb? From a simple look? "There's no harm taking a day to ourselves, and I do remember promising you that I'd make going to the aquarium as a family worth your while…" He trailed off with clear intent.
Holy fuck. Had his mom really only agreed to hang out with him because she wanted to get fucked!? That hag! 'Least Katsuki got enjoy her reward, which really, he had to put up with his mom too. And now trapped in her body, he felt he had more than earned it fair and square.
Instead of showing the simmering irritation, he let his eyes fall half-lidded and licked his lips. "Then I guess we have to get our work done fast enough… wouldn't want to have to rush the good part." He felt absolute glee watching his father close his eyes and groan. Yeah… this was going to be fun.
Okay… Maybe Katsuki hadn't thought this through, sure he had briefly pondered how his own inexperience might make fucking his dad in his mom's body a bit complicated. But, the whole situation was a cluster fuck, so surely it couldn't make it much worse.
Whatever, it's too late for thinking about that now. He was already half stripped and laid out on his parents' bed, ready and willing for his father. "You seem a bit subdued today… you must've been desperate, huh? I'm sorry, Love, I should've made more time to take care of you." Fuck… if his dad kept talking like that…
A high pitched, feminine, moan forced its way through his clenched teeth and Masaru chuckled with delight. "Or maybe I should get you like this more often, I love hearing how vocal you get." If Katsuki were in his right mind he would've recoiled at that sort of teasing, but as it were, it just made his cunt clench and his eyes roll back.
"Fuck- Masaru. We don't have all fucking day, just hurry up already." He tried to demand, but his voice was far too whiny and his desperation just made it sound like a needy plea. It was pathetic and it pissed Katsuki off enough to rip his panties off himself and shove two fingers into his sopping hole. "Or do I have to do all of the work?"
Instead of growling or reacting how Katsuki had hoped (Immediately fucking his brains out), Masaru just smiled at him so fondly it made his stomach swirl. "Alright, Mitsuki. Anything you want, but I'm not rushing it. We have enough time and I want to make the most of it."
Making the most of it apparently meant eating Katsuki out until he had tears running down his face and couldn't stop trembling. And the worst part? He was still going. Masaru's tongue worked its way inside his quivering hole before slowly trailing up to his clit. It was soft enough to not feel like glass was pressing into the sensitive skin, but each press felt like a mini orgasm of its own.
The sheets under him had gotten absolutely soaked, but he was far too out of it to truly mind. That was an issue for his dad to deal with later, it was his fault in the first place for being so damn good with his tongue. And after being forced into another mind numbing orgasm that made his entire body clench up Katsuki forgot about it entirely.
"Mmh, you always taste so sweet for me, Honey. I could never get enough of it." Masaru's praise felt more like a threat considering Katsuki was still feeling the ripples of pleasure pulsing through him.
Before Masaru could even think about going back in Katsuki had a handful of his hair and was yanking up and away from his sensitive cunt."You're fuckin' crazy." It's hardly a broken whisper, forced out between panting breaths. "If you want to even think about fucking me after that, you are going to give me a second to recover and a glass of water. You tryin' to dehydrate your wife or something?" Katsuki knows he just looks pouty, but he tries to stay firm.
Masaru is entirely undeterred, perking up like a fucking dog and agreeing immediately. You'd think he forgot the whole goal was to get his dick wet until now. Who knew what a pussy drunk, perv his dad was. The brief moment alone did allow Katsuki time to really consider what he was doing, this could ruin his parents' marriage if his mom found out. And his dad would feel pretty shitty too… the thought makes him sigh, but he's in too deep now. Hell if he's giving up the chance to get dicked down when he's this close. Fuck morality.
It was just in time that Masaru came back, Katsuki was feeling a lot less like a bus had driven over his entire lower half and he'd regained his resolve. His dad brought the glass of water and gave him a smile that was a disgustingly sweet, adoring thing. It did NOT make his heart flutter, nor did it inspire a wave of jealousy that this look had been meant for his mom.
Katsuki rolled his eyes at himself and chugged down half the water, he could feel the immediate relief in his body. The slight pain and dryness of his eyes from crying had dulled and his mouth no longer felt like it was full of cotton. All in all, Katsuki felt ready to keep going.
"Alright, get over here and lay your ass down. I'm not letting you set the pace after the shit you pulled." Masaru chuckled, but obeyed. He always looked so fond when Katsuki tried taking any control, like he was some brat.
His dad was set up in the middle of the bed, relaxing against a pillow so he could sit up a bit, he was still wearing his pants though, which was an issue. "I'm sorry I pushed you too far, I was sure that you could handle it is all."
"I'd say I handled it just fine!" The quiet, challenging glint in Masaru's eyes had Katsuki excited though. He couldn't take the wait anymore, he needed to be filled. Katsuki made quick work of taking off his dad's pants and boxers in one movement, not even bothering to pull them past his knees. Then, just because he was feeling nice, he removed the shirt he still had on slowly. The hunger in Masaru's eyes while he kicked his clothes off his legs nearly had him drooling.
"You're gorgeous." It was whispered almost reverently, like Masaru was so in awe of his wife's body. As if he hadn't seen it countless times before. Katsuki almost faltered, wishing that he could experience something so loving in his own body.
Instead of letting the momentary weakness show, he just smirked. "Yeah? You're not so bad yourself, Darling." It wasn't until he'd climbed his way up the bed, settled just above the cock of his dreams that it hit him. How the fuck do you ride someone? Not wanting to look hesitant, Katsuki starts rubbing his, completely drenched, cunt up and down the length of Masaru's dick while he thought.
Porn was disgusting and unrealistic. That's what Katsuki had gathered, so he never really bothered to watch it. And sex seemed like a waste of time since he'd never dreamed he'd actually find himself in bed with his dad. Some of the romance novels he'd read had some 'spicy' scenes, but they weren't descriptive enough to guide him much.
Fuck it, he'll just shove it in. Katsuki took a deep breath and attempted to line Masaru's cock up with his cunt, he couldn't really see what he was doing, but hoped that it'd just sort of pop in when it got to the right spot. And luckily with how wet and loose his dad's tongue made him… it kind of did. At least the tip popped in, but the way his pussy clenched down in surprise halted him from progressing further down.
"Fuck- relax Sweetheart. You know you can take it, just have to let it in." Katsuki really needed his dad quiet, every word out of his mouth made him lose a little more sanity. Being so fucking hot should be illegal.
It wasn't easy to make his muscles loosen, but taking a few deep breaths and rolling his hips gently helped him work more in. Once he'd gotten used to the slightly intrusive sensation, it was easy to keep inching his way down until finally his thighs met his father's.
Katsuki felt so fucking full he could hardly breath, it was like his dad was pressed against his lungs. All he could do was rest in Masaru's lap for a couple minutes, just catching his breath before he could move again. He started off slow, just using his hips, not wanting to lose any of the cock filling him up so perfectly, but he could tell Masaru was getting impatient.
His dad was starting to twitch a little under him, restraining himself from fucking up into Katsuki. And his hands were wrapped around Katsuki's hips with nearly enough force to leave bruises. He wondered idly how his mom would react if that was how she found out what happened, but the thought dissipated when he lifted up and dropped himself back down on his dad's cock.
They both moaned loudly in unison and that only spurred Katsuki on more. His thighs were burning after a few minutes, making it harder to keep a consistent pace, but Masaru was such an observant husband. He noticed the struggle and decided to help out, using his hold on Katsuki's hips as leverage to start thrusting into him.
It felt so much better letting his dad take control, he clearly had plenty of experience and knew just how to touch this body to make Katsuki see white. Even after being wrung out earlier, or maybe because of how sensitive it made him, Katsuki already felt an orgasm approaching fast. He wished he could last longer, but there was no choice. "Fuck! Dad- ah Darling, g'nna cum- don't stop!"
The slip up made his cunt clench down, wishing he could call for his dad while being stuffed by his cock, but this was enough. It had to be. Fortunately, Masaru seemed too caught up to notice, only groaning, "me too, Baby. Going to fill you up just how you like, doesn't that sound nice?"
Katsuki nodded, choking out moans of approval, growing in volume with each thrust. "Yes! Fill me, please! Need it- need your cum!"
He's the one to cum first, but Masaru follows almost immediately after, the way Katsuki's cunt restricts around his cock was just too much. The moment his dad finally stopped moving he collapsed forward into his arms. He could feel the mess dripping out of his cunt in uncomfortable spurts, still trying to catch his breath, when he heard it.
The door slammed open and there his body was, furious and shouting, "What the FUCK is going on here Katsuki!?"
Shit.