ꉂ ᵎᵎ cw/tw: 18+, stepcest, switch!older step-brother!izuku, switch!brat!fem!afab!18-20y/o!virgin!younger step-sister!reader, college!au, teasing. everywhere. corruption kink, grinding, domination loss, yandere behavior, insults, alcohol mentions, smoking mention, discussion and brief imagery of usage of sex toys, not proofread by a lucid author, no beta we die like bakugo, usage of onii-chan, possible non con elements, morals be damned— that girl can cook! (dark content), girl idfk what else to tag
ꉂ ᵎᵎ a/n: my name is dot and sometimes i make typos or write bad but i go to sleep instead of fixing such problems. from my lovely ask from lotus nonnie
ꉂ ᵎᵎ synopsis: curious step-sister asking her step-brother questions she shouldn't really be asking.
ꉂ ᵎᵎ w/c: ~2.5k
“hey. have you ever had sex?”
izuku nearly spits out his drink, eyes flicking from the tv to where you sat on the couch. “excuse me?” he asks, half hoping he’d heard you wrong. he sets his half-empty can of beer on the coffee table and leans closer towards you, as if getting nearer might somehow further clarify what you asked. considering this was the first real conversation he’d had with you since you moved in to his apartment for college — and that it was about sex, of all things — you couldn’t exactly blame him for being caught off guard.
“have you ever had sex?” you repeat, much too evenly, overt curiosity dripping from your expression.
“i, uh,” he clears his throat, cheeks pink as he briefly debates whether or not to answer you. “yeah, i have,” he murmurs at last, a little nervous chuckle slipping out. “—why are you asking me this?”
you shrug, the movement seemingly blithe. “i dunno. you never have any girls over. or guys. like, in that way. and you smoke and drink all the time, so you must be stressed,” your hand lifts to toy with the strand of hair that fell over your forehead, thumb and index finger rubbing it absentmindedly. “i guess i just wondered if you’ve tried getting your rocks off before doing all that.”
his brows furrow slightly at your pragmatism, the tip of his tongue brushing the back of his molars in a introspective lick. what exactly was your aim here? it had been a couple of years since he’d last seen you, but he’d always known you to have a bratty streak— by the looks of it, he could only assume it had simply… faded with your blossoming adulthood. “huh. i had no idea you were so concerned with my… health,” your step-brother drawls, before letting out a humorless chuckle. “you sound like my mother.”
you only offer him another shrug in response, resting your chin against your palm, your elbow creating a soft indent in the couch’s arm. “it’s all she would talk about when you left home. she told me to keep an eye on you once i moved here.”
“so you’re gonna tell her i’ve had sex?” izuku asks dryly, brow arched partially in confusion, partially in mild annoyance.
“no,” you answer simply, taking careful note of his analytical gaze. “but i’ll probably just say something like you’re not relieving your stress properly if i talk to her.”
“relieving my stress properly…” he repeats slowly. a puff of amused disbelief escapes through his nose, and he decides to try to crack a joke, hoping to steer the conversation away from the idea oversharing with his mother and maybe make you embarrassed. “and i take it you’re some sort of expert on… ‘stress relief?”
much to his surprise, however, you shake your head, more honest than he anticipated. “on sex? nope, never done it,” you hum lightly, “i just know that it’s like, important for people to do a bunch of it in college to explore themselves or something, and well, that it’s like, good for stress.”
his mouth opens to speak but closes when no words come out, not really quite sure how to respond to that. “well, that’s true,” he coincides, “but like— i don’t know about a bunch of it…” he shakes his head, getting caught on your confession of virginity. “—wait, you’ve haven’t done it yet?”
“yeah,” you reply, a subtle disappointment tangled with worry in your voice. “am i supposed to have? i wasn’t sure what age would be the best to lose my virginity, but i thought a drunk experience would be a good story, so for the moment i’m deciding on twenty-one.”
izuku purses his lips, his head quick to shake in objection at your terrible plan. if he didn’t know any better, he would have thought you were purposely trying to provoke a reaction out of him. “no, no— you definitely don’t want to lose it while drunk— what? i—, yeah no, no. no way that’s happening while you’re staying with me,” he lets out a huff, trying not to seem so affected by the idea. “do you even have a person in mind to fulfill this… plan with?”
your following shrug does nothing for his worries or the odd aching sensation in his heart. “i dunno,” you murmur, “some frat guy at a party i meet? i like frat guys. they’re usually tall.”
“i—” he frowns, the idea of some bumbling… meathead messing with you deeply unnerving him. “girl, no— frat guys are out of the question. i’m talking about a boyfriend. do you— have you ever even had a boyfriend?”
“nope,” you answer promptly, letting the “p” pop for emphasis.
“okay, well,” he clicks his tongue, feeling strangely… happy about your answer. he pushes the feeling down. “your first time, whenever it is — because you shouldn’t have a set date or goal in your head — it should be with someone you really care about and vice versa. you’ll want it to be special, because like, sex is supposed to be special. okay?”
you nod slowly, almost as if you were really letting his words sink in. it’s all the reason why he’s not at all prepared for what you ask next. “so, was your first time good, izuku?”
the familiar rush of blood spreads throughout his face at once at your question, and he lets out a nervous chuckle. “uh… i would say it was,” he stammers, before becoming overcome with the need to be didactic, “but y’know actually, now that i think about it, sometimes it’s not gonna be that good and that’s okay. i think setting expectations might actually lead to disappointment…”
you blink, confused. “so my first time is gonna be bad…?”
he gives his teeth a sharp suck, at a lost for the right words. “no, god, i hope not— it’s, no, or, well,” he takes a deep breath, trying not to let his flusteredness get the best of him. what on earth brought on this surge of curiosity in you? “y’know, it might be, it might not be. if you’re with someone who has a little experience, it’ll be a thing the two of you will learn as you go. if you’re with someone who knows what they’re doing, it’ll probably go a bit smoother because they’ll probably be able to tell you what to do. but, it’s also possible they know what to do but are just… bad at it. it all depends.”
when you nod with some semblance of understanding and redirect your attention back to the television’s screen, he thinks that’s the end of it. however, time and time again, he’s proven wrong.
“do you think i should invest in sex toys, izuku? to prepare myself?” you ask, head flicking swiftly back his direction.
his teeth meet the inside of his cheek in a bite, the tips of his ears growing red at the particular subject at hand. you notice the way his gaze avoids yours, obviously trying to ignore the way you look at him— like how a little step-sister shouldn’t look at her big step-brother. “...pardon?” he asks, although he heard you perfectly clear.
you can’t stop the mischievous giggle that slips from your lips, your intentions betraying you despite yourself. inch by inch, you shift closer to him on the couch, fully aware of the way his breath catches with every small movement you make. “like, y’know,” you casually explain, “buying a dildo or something. to stretch me out.”
he clears his throat, the quick mental image of you — stuffing an oversized piece of silicone into your little pussy, over and over — flashing through his mind, not necessarily sure if it’s unwanted or not. “i mean— i guess,” he mumbles, “it is healthy to explore those sorts of things but, it’s, it’s not usually necessary— y’know, i, i’m not really sure we should talk about this sort of thing—”
“do you use toys, izuku?”
“um…” he swallows thickly, trying not to look into your inquisitive eye. “not really, no.”
a disappointed sigh escapes you, your warm palm settling on his knee through the fabric of his sweatpants. his gaze drops to it instantly. “another bad thing to the list,” you murmur.
“what?” he asks, immediately seeking clarification, mouth dryer than he’d like. “what bad thing?”
“lying,” you say astutely.
“lying? what have i lied about?”
you roll your eyes lightly, unable to hide the smile that curls your lips as you press your cheek against his bicep. “you have a fleshlight in your room in the hidden compartment of your nightstand. it’s next to the polaroids you took of me when i was sleeping.”
izuku reels back from you, his breath hitching as words fail him, caught completely like a deer in headlights. a rush of heat — and something heavier, like shame — washes over him. “i—” he chokes, his attempt at an explanation dying on his tongue as you rise from the couch to straddle his lap, pressing his back against the leather cushions when you do. “hey! what— what are you doing?” he stammers, panic and something else flashing across his eyes.
“nothing,” you hum unconvincingly, guiding his trembling hands to rest on your hips, your clothed pussy sitting right on top the growing tent in his sweatpants. “just trying to see something.”
“and you need to be sitting on me to see?” he asks, still managing a tone of incredulousness, “dude, i— i think you should get off—”
“why?” you tilt your head, acting innocent, the words wrapped in a faux sickly sweetness, “how else am i suppose to feel you getting hard for me?”
“you’re not supposed to feel me doing that,” he groans, resisting the urge to buck his hips up against you, making no real move to push you off. “shit— bro, we can’t do this.”
“we’re not doing anything, onii-chan. and if we were…” you lean in close, your breath ghosting against the shell of his ear, “...would it be so wrong? we’re not actually related.”
he says nothing, his breathing uneven, and a small mocking smirk tugs at your lips. “mommy and daddy aren’t here to tell us what to do, izuku.”
once again, a lack of reply continues— his mind struggling to catch up. grinning, you pull back just slightly, noticing the way his gaze flickers quickly to yours, and your hands rise to cup his cheeks. “onii-chan,” you mumble, a whiny-like charm to your vocative, “do you think you could teach me how to kiss?”
“you don’t know how to kiss?” he manages at last, voice cracking when he finally speaks.
“mhm,” you nod, fingers trailing tenderly over the freckles that adorned his face, before wrapping themselves around the back of his neck. “i’ve been saving it for you. i saved everything for you.”
“for me? wha— why?”
“because i love you, izuku,” you whisper with upmost confession. “don’t you love me too?”
a sharp hiss escapes him as you grind down onto his cock through your clothes, his tongue darting out to wet his lips. “of course,” he admits all too easily, “yeah, fuck— of course i love you, it’s just i— i don’t…”
“you don’t wanna mess up your cute little step-sis? can’t control yourself if i let you have your way with me?” you ask with feigned gentleness, guiding him to finish his sentence— not teasing, just… coaxing. when he nods meekly, you just let out a soft laugh. “you wouldn’t mess me up, izu,” you promise, too mellifluously for your own good, “i’m a big girl. i can take whatever you give me.”
“d-don’t say stuff like that,” he groans, as if hearing you talk like that would make his thundering heart explode on the spot, “shit— you know this is fucked, right?”
you smile at him, watching the way his eyelids droop, heavy with desire. “mm, yeah… but i won’t tell anyone if you don’t.”
he shakes his head, desperate, promising. “never.”
with a soft giggle, you move to close the distance, your lips hovering just shy of his. “plus, you could always blame it on the alcohol.” a brief tantalizing pause stretches between you two as you let the sound of your breathing mingle with the quiet of the living room, whatever show you two were watching long forgotten. you bite your lip deliberately. “so. are you gonna teach me how to kiss, onii-chan?”
izuku nods, clammy hands rising to cup the curves of your cheeks, your voice ringing in his ears. “y-yeah, of course, just come here and…”
just as his lips tremble toward yours… you pull away, giggling at the following confused look on his face.
“you really thought i was gonna kiss you, izuku?” you laugh, leaning back, the mischief in your actual plan now painfully obvious. “jesus, you’re so weird. what’s wrong with you? fucking freak.”
“wh-what?” he stammers, lost on what was happening, eyes fluttering as if that would help him better understand.
to his dismay, you don’t really explain it as well as he’d like to him, the roll of your eyes going very unappreciated. “i wouldn’t fuck my step-brother, you weirdo,” you snicker, giving his forehead a flick — ow — “and i especially wouldn’t give him my virginity either. you seriously believed all that? it was a prank, you idiot.”
you begin to climb off him, but his hands clamp onto your hips, anchoring you in place. your eyes snap to his— and you catch the darkness in his gaze, the heavy rise and fall of his chest. was he mad? sure, you’d pushed it a little far, but your kind, sweet step-brother rarely showed anger— and certainly never at you. it was just a joke! yours hands lift to push at his chest, ready to protest, but a low, chilling and uncharacteristic chuckle stops you cold.
“fuck, you almost had it,” he echoes your earlier laugh, though it rings different, for reasons you can’t quite place. his head falls back as mirth ripples through him. “why’d you get embarrassed? didn’t i play my part good enough? i was all cute and nervous for you.”
“what?” you ask, brows knitting in confusion and irritation, a flicker of unease creeping in at his unordinary behavior. “what the fuck are you talking about?”
he smirks, a hand threading through your hair in a deceptively gentle gesture, like grooming a clueless puppy. “y’know,” he murmurs, as if sharing a secret, “you really shouldn’t leave your diary lying around when you take a nap. you never know who’s gonna find it.”
cold realization hits you like a wave, but you still try to deny it, despite knowing the information he has. “i-i don’t have a diary,” you stammer.
“really?” he smiles softly, too knowing, too expectant. “dear diary,” he begins to recite, and your stomach twists with regret, “i think tomorrow, i’m going to try to make a move on onii-chan. if it’s too scary though, i’m just gonna pretend it was all a joke.” a quiet snicker escapes him, drawn out by your now dumbfounded, nervous expression, clearly enjoying the shift of power here. “you scared, baby?” he cooes, “there’s no need to be. onii-chan can be gentle. i promise i won’t mess you up too bad. just… let me show you, okay?”
ꉂ ᵎᵎ a/n: hi if this is bad. consider this. *pew smoke bomb* (me think it bad so i didn’t keep going)
ꉂ ᵎᵎ cw/tw: suggestive jokes, poly!kiribaku, cute girly fem!reader, fluff, crack maybe, weed mention, non serious threats/jokes of violence, jokes of death, there may be some typos but. do you text perfect 24/7?!
ꉂ ᵎᵎ a/n: idk why this is longer than the bkdk one seeing i like. deku... i think i just didn't feel that confident in this so i had to overcompensate... ermm this was requested ^_^ i decided to do a cutesy reader because. it’s fun and i think she uses light mode and decorated the gc and yeah… also sorry if the conversations are cropped funny. thats just how the dice roll
ꉂ ᵎᵎ synopsis: SMAU conversations about baking, makeup, and video games with poly!kiribaku
ꉂ ᵎᵎ a/n: for those who don't play marvel rivals, you need to level up your account to a certain level before you're allowed in comp, and depending on whatever rank eijirou and you are, there is a possibility that katsuki has to grind by himself until he can play with you guys... it's an act of service <3
Chapter 2: My Reality
I jolted awake, barely registering the sweat dotted along my hairline. As my vision came into focus, I became acutely aware of the pain ricocheting up and down my spine from where I had spent the night on the concrete floor.
I found this old warehouse while trekking to Daegu, or what was left of it, before the night drew cold and I was forced to duck into its crumbling walls for shelter against the bitingly cold winds. It was meant to be autumn now, but with the high concentration of radiation in the atmosphere, the skies were gray and the weather was unforgiving. The warehouse itself was decrepit and falling apart, but still held together enough to be a reasonably comfortable place to sleep for the night.
I wrestled my boots on, grimacing at the dampness inside. After making a mental note to forage for socks when in Daegu, I hurriedly packed my meagre belongings away before shuffling to my feet. After one last quick check that I wasn’t forgetting anything, I stalked up to the grimy warehouse doors and pushed them open.
---
Outside, it was barely noon. Yet, the sky was overcast, a bleak breeze ruffling through the decimated trees that lined what was once a road. The tarmac, once immaculately painted and maintained, was now a cracked mess filled with dust and debris. I trekked cautiously, my eyes darting warily across the road for the slightest movement.
I pulled out a ratty scarf, securing it around my neck and face as a makeshift mask against the polluted air. For miles, it seemed as if the journey was panning out to be an uneventful one - the wind was quiet and the land still. For a brief moment, I allowed myself to wish that I were anywhere but here - perhaps somewhere safe and warm, amidst people who loved me.
Just then, the tranquil silence was broken by the sound of aluminium against concrete. Alarmed, I darted away from the road I had been walking on, slamming my side into a charred tree for cover. My breathing quickened, and I reached frantically into my pocket for my small knife before shakily holding it up to my chest. I scanned the road and surrounding trees and buildings for movement, but everything seemed as still as before. Lowering my knife, I spared one more careful glance across the road before pocketing my weapon reluctantly. Must have been a raccoon, or something. Stop being so jumpy Zula.
I took a deep breath, steeling myself before slinking out of my hiding spot. I’d be damned if I let anything stand between me and my new pair of socks. Unless that anything means death by bandits, or rabid dogs or worse. At that, I felt myself shiver. Just focus on getting to Daegu. Once I get there, everything will be fine.
“Hey!” A male voice called out lightly from across the tarmac.
I jumped, whipping my head around to see where the voice had come from. My hand quickly found my hidden weapon, bringing the small knife out and brandishing it not-so-threateningly in front of me.
“Who’s there! W-Who are you, show yourself!” I called out, cursing my shaky voice for betraying how intimidated I really was. “P-put your hands up!”
A flash of silver caught my eye, and two men emerged from around a large tree across the road from where I was standing, terrified. I could feel my heart pounding erratically inside my chest, and my eyes darted between the two men who were now holding their arms out carefully.
“Hey, hey. Calm down now, there’s no need for weapons.” One of the men cried out, before murmuring something I couldn’t catch under his breath. “We’re sorry for scaring you, okay? We just heard you mumbling to yourself about Daegu and w-we wanted to come along.” He explained, eyes glued nervously on the knife in my hands.
The other man nodded, black hair falling into his eyes as he did so. “We’ve been looking for ways to get into Daegu for a couple of days, but I think we’re lost. We saw you hiding out in that old warehouse a few miles back and decided to follow you. Sorry, that sounds weird now.” He offered gently, his voice barely a whisper.
I frowned at that, slowly withdrawing my knife. “You creeps followed me? All the way here?” I questioned, staring accusingly at the two men. Their eyes followed my hand as I pocketed my knife, both men releasing a breath as I did so.
“Yes, and we didn’t mean to come off as creeps. We just thought it was weird you were travelling alone.” The silver-haired man murmured, lowering his hands and folding them across his chest. His cat-like eyes were focused on my face and I found myself unable to hold eye contact for long.
“So we followed you for a bit down this road, then we heard you talking to yourself about going to Daegu. In hindsight, maybe we should’ve introduced ourselves first.” The black-haired boy chuckled nervously, ruffling his hair.
“Yeah, maybe you should have. Would have saved me from a heart attack. Anyway, I’m Zula, why are you guys trying to head into Daegu?” I retorted, pulling down my makeshift face mask.
“I’m Joshua,” said the black-haired boy, “and he’s Minghao.” Joshua gestured at the silver-haired boy, who put up a hand in greeting. “We got wind of a survivor’s camp in Daegu via an old radio we got to work a few weeks ago. We’ve just had a bit of trouble navigating.” Joshua admitted, his cheeks flushing pink with embarrassment.
Minghao nodded at that, before heaving a sigh at the gravel between his boots. “The maps we had were not the most accurate, and we travelled in circles for days before ending up here.” He clicked his tongue in annoyance, and glanced briefly at Joshua before continuing, “We think Josh’s parents might be at the camp. So we’re really hoping you can help us, Zula.” Minghao’s eyes came to rest on my face, and I couldn’t help but avert my gaze again.
“S-sure. You guys can tag along, my directions seem pretty good if I got this far.” I jested lightly, and Joshua offered a small smile in return. “As long as you guys swear you’re not up to no good.” I finished sternly, placing a hand over my pocket where my knife was hidden.
Minghao scoffed before arguing: “C’mon Zula, if we wanted to do something we would have already. Be sensible.” I bristled at that and a look of disbelief came over my face. I saw Josh suppress a giggle as he craned his neck away from the conversation, pretending to be invested in the charred shrubbery nearby.
“I’m joking, I’m joking. Can we get a move on? Please?” Minghao chuckled, raising an eyebrow at my reaction. I grimaced before pulling the scarf around my neck to cover my nose, beckoning them over as I yanked out my map from my backpack.
When the first atomic bomb dropped on the city of Busan, the once peaceful fishing city was reduced to nothing but ash and dust. The once vibrant markets were now barren landscapes, adorned with charred remains of buildings, homes and people. The foul stench of decay and burning plastic permeated the air for days, an acrid smell that drove survivors in hordes to the city of Seoul where help was promised.
Days after the first bomb was dropped, people all over Korea were still reeling in shock. The government scrambled for answers, and people clambered over each other at press conferences demanding explanations for the rising death toll and unprovoked attacks. Radiation sickness was rampant in hard-hit Busan, and many didn’t survive after being pulled from rubble.
In other cities, paranoid citizens looked urgently to their leaders for guidance, and were met with a stifling silence. Many resorted to poorly made shelters, and within weeks, stores were cleared of essential goods like canned food and medicine. Everyday life seemed to go on per normal, but the looming fear of a second attack kept citizens on the edge constantly. Government leaders tried to urge citizens not to panic, with leaflets on how to stay safe and watch for danger being handed out at every corner.
Every day, news of Busan’s ravaged cityscape was blasted on television screens nationwide. Ghastly images of those suffering from radiation poisoning would soon become a norm in Korea, with people watching on in horror as their fellow countryman suffered and died agonisingly.
This would go on for two more months before the rioting began. It started with a rumour - a poorly formulated theory on the origin of the attacks that soon spread like a wildfire, poisoning the minds of the people with lies and deceit. As resolves crumbled, superstitions grew. People turned to prayer, hoping for salvation in the hands of a higher being. This, of course, was not to be true. Claims of an independence day began to circulate viciously, with people living their every moment in fear. Government efforts to urge people to stay calm and refrain from engaging in misinformation fell on deaf ears, and in a moment of panic, people started to hoard supplies in preparation for a second bomb.
Days went by, and the once serene streets of Seoul were now littered with debris, shattered glass and other paraphernalia from the endless rioting. During the day, it was quiet - riot police stood guard on every pathway, ready for confrontation. By night, roads were filled with angry protesters, demanding explanations for the attack, fighting the police with anything they could weaponise. The resulting weeks would be remembered as some of the bloodiest in history.
For a while, this was what life had become. People were lulled into a false sense of security, and for a fleeting moment, it almost seemed as if a second attack was nothing but an irrational fear.
So when the second bomb plummeted into the capital of Korea, people were caught off guard. In the final moments before the bomb made contact with the ground, people stampeded in an effort to put as much distance between themselves and Ground Zero. Bloodcurdling screams filled the air, and for a short 10 seconds, all that could be heard was a shrill ringing before a blinding light bloomed and sent an enormous shockwave across the city. The shockwave levelled buildings, scorching everything in its path and destroying anything within a 10 kilometre radius. Screams were replaced with the unbearable sound of wind ripping past your ears and the clatter of debris raining down onto the ground. And then, silence.
I had been in school when the second bomb was dropped, laughing along to something my friend Hyunjin had said. I recall turning to the window on my left, resting my cheek in my palm as I took in the calm midday scene outside the classroom. I had plans to visit the arcade before returning home later, as a means to work off the pre-examination jitters before finals week.
I remember seeing a bright flash of light in the distance, followed by guttural rumbling reminiscent of a large earthquake. The last thing I saw was a large, grey mass filled with debris and dust before I was slammed off my chair.
