he'd never! (he would) | ft. ishigami senku
word count: 1.3k
cw: exchanging nudes, male masturbation, senku's horny, horny thoughts
18+ mdni, ao3 link
It's the last thing anyone would expect from him. But irrationality is a prolific criminal; it shows up where love is welcomed.
For once, something that has nothing to do with science is plaguing Ishigami Senku's mind. Even his colleagues knew something's up when he was seen checking his phone on numerous occasions and fidgeting with just about anything he could get his hands on, as if he needed a constant outlet for his nerves. Nobody could talk to him without being interrupted with a "Huh?" or "Repeat that for me?" at least once. Then he'd be back to looking preoccupied as soon as the conversation was over.
Others chalked it up to an off day. Sure. Everyone had those from time to time, even the science messiah himself. Some secretly believed he had a breakthrough on something of a cosmic-scale and it was too early to divulge his hypotheses.
They weren't completely wrong, he'll give them that. But they’d put him on such a high pedestal, it never occurred to them that, at the end of the day, he was just a man with a healthy amount of testosterone. And biologically speaking, that made him pretty simple.
"Fuck—fuck, fuck, fuck, that's so hot." He cards his fingers through his hair, slightly damp from sweat, closing his eyes in sheer disbelief at the sight in front of him. The toilet cover's down, stall locked, bathroom empty, and his belt's unbuckled to free his hard, aching cock into the cold air. A clear, glistening pearl of slick threatens to slide down his veiny length.
You've got him hard in the middle of work hours—just from a few mirror shots. The room is dark, save for a nearby lamp's glow. You're wearing one of the oversized tees he got as a memento during a science summit some months ago. Any kind of memory he has of it—the things spoken behind the podium, the collaboration of great minds, the wonder in seeing inventions unveiled in front of a stage—has been completely overridden by the sight of you lifting it high enough to show your beautiful, squeezed tits. No bras, no nothing. Just your sensitive, pert nipples rubbing against the very fabric he's worn a dozen times.
The thought sends a wave of lust right down into his balls, and the tightening sensation makes his brow twitch.
Another photo—god have mercy—was taken by your front cam. Legs spread open, damp, lace panties slid to the side—freshly shaved too, fuck—capturing the same line on your pussy he's ran his tongue up against more times than he can count. The glimmer across your inner thighs suggest you've been up to no good for a while, and the photos were only one of the many things you've probably done.
His imagination betrays him by flashing a hundred possible scenarios at the speed that he would've appreciated back in an earlier meeting.
You included a little message that said, Don't work too hard, Doctor.
Don't work too hard, Doctor.
Don't work too hard, Doctor.
Don't work too hard, Doctor.
Senku could almost hear you saying it right into his ear with a little lick, a little nibble.
He scrolls down to another photo, one you sent more recently, just five minutes ago. Five minutes ago when he was still holding onto his last straw. Five minutes ago when the vibration from his pocket completely eviscerated what little self-restraint he had left.
His heart picks up at the image.
You're under brighter lights this time, the collar pulled to the side, showing the ruin his mouth had inflicted all over your pretty neck and shoulders—a constellation of purpling marks of all shapes and sizes, the indentations of his teeth where he'd sunk them on your shoulders now half-faded—a testament to his filthy hunger, and you let him have his fill.
Missed a spot, you wrote. Send one back?
Senku wastes no time. His fingers expertly navigate through the interface of his phone and swipes his way to the camera, where the sight of his hand gripping the base of his thick cock was already set for a photo. He's particular with his angles despite the fact that he has all the important bases covered; he makes sure the light is hitting his shaft at a perfect angle, and that his tip's in good color. Most importantly, he sees to it to include the very thing you loved the most—a flash of green, the same color he had at the tips of his hair, deliberately untrimmed for some time.
He types in, Bet you miss it already.
His fingers work on unbuttoning his shirt next. He keeps his tie aside, and pulls on his shirt enough to show the very same marks spread across his chest and shoulders in equal measure. The first thing that comes to his mind is the memory of you sobbing and suckling on his skin as he kept himself fully sheathed in your cunt. And the way he knew, that you knew it was only going to get more intense.
Thought you might wanna see your handiwork too.
It doesn't take him any effort to cum, not when you've supplied him with plenty of material to work with. His mind is deep inside the gutter. He recalls every lewd sound you've made in vivid detail. He recalls the way your pussy lips puff up adorably when he's been inside for too long. Or the obscenely creamy sounds you make when he's creampied you more than once, the way it looked so perfect dribbling down the curve of your ass.
Or the way you sounded when he's fucking you from behind, one hand holding onto your ankle, the other by the column of your throat. How your lips swell from sucking him off too long, glassy-eyed and stupid with want, tongue still flicking at the slit on instinct. You always slobbered and gagged on his cock, taking him all the way in your mouth until his curly hairs tickled your nose, and fuck, he'll always be weak to it, no matter what.
Senku manages to get it on video, the spurts of thick, milky ropes into his palm, trickling down his cock. His breaths are short and heavy. He knows you'll love it. He knows you'll touch yourself to it, and he knows you'll want to choke on him again as soon as he closes the apartment door. You'll whine and nag and beg and tease, only to end up babbling and clutching onto him for dear life by the end of it.
He wipes himself clean with a generous helping of tissue paper and coughs a few times for good measure, in case someone had walked inside when he was too busy jacking himself off to a bunch of pixels on a handheld screen. You’ve turned the Chief of Science into a cum-addled mess in the company restroom. And he’s going to give you a piece of his mind—gratitude—whatever he's in the mood for later—when he gets home.
The flush seals whatever transpired in the four corners of the cubicle for good. He washes his hands, fixes his hair a little, smooths out his clothes and walks into the hall with his usual air of confidence.
I ate too much corn yesterday—that's going to be his excuse, yes. Perfect. Not too absurd, not too vague it borders on suspicious. Nobody would suspect a thing, because the thought of Ishigami Senku doing something so appalling and beyond all scientific reason was uncharacteristic, and that whoever insists it's true must be a jealous, immature liar who resorts to petty defamation. He would never stoop that low. Not for anything. Not for science!
senku wants a human lab rat, but what could he be testing that required you to be tied up naked on his bed??
18+
cw: rope, soft dom senku, p in v, alcohol, slight humiliation, fingering, face fucking
word count: 3.4k
part 1 part 2
chills down your spine. senses on high alert. the feeling of smooth rope wrapped around your wrists. a bush of green hair enters your field of view. senku, who’s perched over you, is messing with the knot on your left wrist.
you’re lying on your back; bare skin flush to the bedding beneath you. arms constrained, with your hands above your head to the frame of the bed.
on your left there was a nighttable with what seems like a bunch of lab tools neatly lined. something stood out though. you squint.
is that a condom?
“senku, i don’t know about this.” you hesitantly confess.
senku reaches into the right pocket of his lab coat, pulling out a folded sheet of paper. “but you already agreed.”
he extends the now unfolded paper towards you. at the top in big letters “consent form.” and at the bottom in black ink, both yours and senku’s signature.
hastily scribbled, but definitely yours.
———————
“everyone! shots on me tonight!” shouts an obnoxiously inebriated ryusui on top of bar francois’ counter. cheers erupt across the ship with some whooping and whistles.
“aren’t shots on him every night?” senku mumbles into your ear. bumping his shoulder into yours.
feigning nonchalance at the proximity, you reply, “i don’t know,” a queasy feeling twists in your stomach, “but i don’t think i can drink anymore.”
with his usual cocky smirk, senku snarks, “yeah, you definitely can’t.”
“its just,” a hiccup, “too damn loud.” you say while rubbing your temples.
senku stands and extends his hand, “you wanna go to my lab?”
you accept his offer and clasp his hand, letting him navigate you around the ship. feet dragging and eyes blurry as your mind slurs from the alcohol.
senku doesn’t typically allow anyone inside his lab, excluding dr. xeno, of course. everyone just assumes it’s nerdy science stuff and leaves him to his own accord. you can’t help but feel a little honored at the invitation.
senku carefully guides you through the dark oak door of his lab and shuts it behind him. the hand you held now somehow evolving into an arm. unconsciously, you lean into him for balance.
senku, who’s feeling a little bold, places his hand on your waist. he tugs you towards his desk. though it's messy with stacks of blue prints and notes, you’re charmed by his dedication to better the village.
still holding onto him, you take in the new scenery. it’s quite the spacious room despite it being below the deck of the ship. decorated (if you can even call it that) with test tubes, goggles, and little trinkets that he probably forced kiseki to craft.
in the corner is a queen sized bed, plush with the gray variant of yuzuriha’s Five Piece Ultra-Soft Down Alternative Comforter Set with Sheets™
“you can sit here,” pulling out an extra chair from under his desk.
before you can respond, he starts to ramble, “it’s quiet in here, right? i tested the oil we found from that reservoir we found recently, right? guess what? it was crude oil! or as you may know it, petroleum. well, i processed that into styrene and then used pentane as a blowing agent. boom! stone world styrofoam! i installed that into the walls of this room as makeshift sound proofing!”
processing none of that, you slump into the chair, replying with a, “dude that’s badass.”
humming a sound of agreement, “right? made it cause i felt bad for ukyo during late night experiments.”
senku slides into the seat next to you. fiddling with your fingers, you feel a hand creeping up your shoulder. too drunk to say anything, you lean into him as approval. basking in the comforting silence, he plays with your hair; twisting it between his fingers.
senku breaks the silence and lifts his arm, “do you want water or anything? hydration is important when you’re intoxicated. it’ll help with your inevitable hangover tomorrow morning.”
guessing the moment was over, you sigh, “yeah get me some water please.”
immediately jumping up, senku grabs a medium sized beaker (a beaker!?) and fills it with the water vase nearby. he fumbles with a drawer and pulls out something you can’t quite make out. taking steps back to you, senku extends the beaker and a pill.
you grab both, popping the pill under your tongue and then washing it down with water.
he raises his eyebrow, “you’re not even gonna ask what its for?”
putting the beaker back down, “senku, you’re a man trying to revive the whole world. whatever it was, it couldn’t have been bad for me.” you say, running your hands through your hair.
he lets out a breathy chuckle, “well it was an electrolyte tablet. you trust me too damn much.”
“i’d trust anything you’d do.”
“anything?” his eyebrow quirks.
“yeah?
“you’d let me do anything?”
“i’d probably even let you run experiments on me.” you snort.
there’s hesitance before senku speaks, almost as if he were picking out the right words to say.
he leans over, placing his right arm on your seat and shifting his weight to it. the change in distance instigates panic within you.
fuck, you’re so down bad.
he slowly opens his mouth, “are you serious? would you let me experiment,” a pause, “on your body?” senku’s eyes lock with yours expectingly.
heat creeping up your neck, you avert your eyes. in any other situation you’d retort with something along the lines of ‘just kidding!”
but, maybe it's because of the alcohol in your system, or maybe it's the undeniable attraction you have for the man. you find it nearly impossible to reject his eagerness.
i mean look at that face.
that handsome, handsome face.
that jawline.
chiseled and aching to be seen.
that-
nope.
you can’t look anymore.
eyes now glued to your shoes, you sheepishly cough out an, “uhm, i guess.”
“wow,” senku grins, “i have to record this moment.”
senku turns around, back towards you and hunched over his desk. drunk, confused, and now embarrassed, you’re almost relieved he’s no longer looking at you.
unfortunately for you, the panic from his proximity hadn’t subsided and any attempts of thought diversion weren’t working.
senku turns, whipping out a piece of paper with some writing on it.
he thrusts the sheet in front of you, and again, placing his hand at the seat of your chair. he excitedly speaks, “you meant what you said, right? if you meant it just sign here, at the bottom. first and last name.”
the distance between you guys closed again, you squeak a panicked noise. your hand scrambles to the fountain pen on his table and quickly scribble a signature.
“okay! whatever! just, back up!”
it can’t be that bad right? maybe he’ll just make you test new medicine? like a human lab rat!
he steps back, an ill intended smirk appearing on his face before quickly disappearing. “well you seem to be doing better. wanna go back up?”
you stand up and take a step, almost tripping over your own feet. stabling yourself on senkus desk, you agree, “yeah, let’s do it!”
ryusui spots you and senku walking up the stairs. “where have you guys been?! you’re missing the main event!”
with a secure grasp on your arm, senku asks, “what’s the main event?”
“me! of course!” ryusui shouts boisterously, simultaneously snapping his fingers and summoning his trusted butler, francois. seemingly popping up out of nowhere, they offer a plate of assorted alcoholic beverages.
———————
with the rest of the night a blur, you end your recollection session.
when you woke up, you were already constricted and exposed.
“senku. i know i said i’d agree to the experiments, but i thought you were gonna, i don’t know?! test substances on me?”
retracting the consent form, he wags his fingers, “no loopholes. a contract’s a contract.”
“since when was it a contract?”
“what? sorry, didn’t hear you.” he quips while walking towards the nighttable on your left.
the corners of his lips twitching, senku bites back his smile. “like i said, i’m gonna run some experiments on you.”
still freaking out; you ask, “what kind of experiments require me to be like,” you try pointing to your current state, but forget that your hands are bound, “this!?”
“just go with it, will you?” senku looks up at you, “i didn’t strip you. if you were wondering.”
what? if he didn’t, then who did? clearly perplexed senku continues, “you came down here after the party and fell asleep on the floor. i tried taking you back to your room but apparently you sleep naked cuz,”
you gasp.
“you started taking your clothes off, grumbling about how it was too hot.“
“oh my god, i’m so sorry, i didn’t mean to-,” you pause, “dude that doesn’t answer why im tied up to your bed.”
realizing his experiments weren’t going to proceed if he didn’t explain himself, he lets out an awkward laugh, “uhm, yeah about that. i may have wanted to redeem my ‘do anything to you’ pass. and i might have been afraid you’d try to run.”
“of course i’d run!”
“see! just go along with it! it’ll be quick.”
giving up, you sigh, “what are you gonna do to me?“
“figure it out. you’re a smart girl. i saw you looking at the equipment.”
oh yeah. the condom.
“senku are you trying to fuck me?”
though bold before, senku turns, clearly embarrased. he denies, “no! i just wanted to.. test some hypotheses. you know, about like, human reactions to different stimuli. specifically, like, sexual stimuli?
yeah he wanted to fuck you.
scientifically fuck you.
“you’re lying out of your ass right now.”
“whatever, yeah i am. look, i read a book about intercourse before petrification and i wanted to try it.”
“why didn’t you ask?”
“i did, you said you’d let me experiment anything,” he pouts.
this idiot.
telling someone you like them is difficult.
though, if anytime’s an ideal time for a confession, it…
definitely wasn’t now.
definitely not when you’re chained up to a bed with a mattress filled with straw. and definitely not when you’re butt naked and eagle spread.
nevertheless, you build up the courage. “if you asked, i don’t think i would’ve said no. i’ve literally had a thing for you since you revived me.”
“i know. you weren’t very good at hiding it. like when i dated luna. which was for political reasons by the way,” he adds on, as courtesy of your eyeroll.
“you know what, you also didn’t seem very happy when you found out i was in that other political marriage with ruri. oh and remember when-,”
“okay i get it,” you cut him off, face hot from embarrassment. guess you weren’t as subtle as you thought.
he places his hand above your left shoulder and hovers over you, “so, may we continue?”
adverting your eyes again; you should say no. you really should. but the idea of senku’s slender hands on you, exploring, feeling, touching.
just the thought sent heat to your core.
“yeah.” you nod shyly.
from his position, he lowers his face in front of yours. crimson eyes holding you hostage before they lid. he kisses you, gently. lips barely even moving together.
slightly pulling away, he stares at you. gazing longingly, like you meant something. pink flushing his ears, he leans back in. this time deeper. his tongue drags across your bottom lip before slyly sliding into your mouth.
mouths now moving in sync, senku climbs over you. his legs straddling both sides of your body.
biting and sucking your lower lip, whimpering every time he bites a little too hard. his hands run down the side of your frame and rest at your ribs, right under your chest.
you inhale sharply when he moves his hand up and lightly squeezes your breast. he rubs your nipple in circles before giving a little pinch. your chest leans into the contact.
he breaks the kiss to lick and suck at your neck, leaving marks scattered as evidence. slowly moving down, making progress down your collarbone and then to your sternum.
he pauses before reaching your breasts. eyeing your reaction, he locks his lips onto your hardened nipple. senku swirls his tongue in circles around the areolar, occasionally nibbling and sucking at the raised peak.
“mmph!” your hands thrash at your restraints.
he lets out an airy chuckle, “see? i knew you’d try to run.” you twitch at his breath chilling the spot it was once on.
he latches onto the other side, like he was making sure it wasn’t neglected. senku smiles against your chest, seemingly enjoying your attempts to break free.
you yelp when he bites down harder than before.
“what? you didn’t like that?” he cheekily looks up.
the feeling of his lips still lingering, you cry out, “no! just didn’t expect it.”
“no, its okay. we can stop,” he lifts himself off of you and hops off the bed.
“what?! why?”
clearly enjoying your desperation, senku wipes the shit eating grin off his face before turning back around.
he grabs the clipboard and the pen off the table and writes out loud, “experiment one. oral breast stimulation. subject response level,” he hums, “mm, a two? what do you think?”
exasperated and flustered, you whine, “i don’t know!”
pretending to immerse himself in his clipboard, he disapprovingly hums and shakes his head, “that’s not gonna work. i need accurate data. we can’t continue if you don’t cooperate.”
“i’m not doing this.”
senku sets the clipboard down and works to undo your restraints, “okay, i guess we’re done then.”
fuck. guess your pride can wait. “no wait! l-like a three?” eyes flicking to everything but him.
cocky, he jots, “a three. okay, noted.” setting the clipboard back down, he crawls back onto the bed and softly caresses your face. his hand moves to your shoulder, then to your stomach before lowering to your throbbing core.
insides bubbling from anticipation, you bite your bottom lip. palm on your abdomen, senku places a thumb on one of your lips and pulls it to the side. unveiling your inner folds, he tenderly blows on your glistening clit.
squeezing your eyes shut, a sharp exhale escapes.
“experiment two.” senku mumbles from below you.
a warm, wet sensation envelops your clit. you gasp, holding back moans as he laps without warning.
his tongue starts off slow, applying deep pressure to the hood of your nerves. wrestling around it in circles before unforgivingly flattening his tongue and pressuring upwards.
“fuck!” a wave of pleasure ripples through your body.
he hums against your lips, happily eating away like a starved man. thinking that his hands needed to pick up slack, senku inches two lengthy fingers into you.
caught off guard with the sudden intrusion you let out a high pitched cry and clamp your legs shut around him.
releasing his hold on your clit he warns, “keep them open, unless you want me to tie your legs down too.”
you hesitantly pull your legs apart.
“b-be nice then.”
“no promises.” he teases.
thrusting his fingers slow and deep, you feel your whole body freezing up trying to adjust to the new sensations.
still eating away, you are left in a frenzied state when thrusts faster and adds a digit without warning. your breathing staggers when you feel an orgasm build up.
“w-wait,” you stutter, “i’m about to-” he laps faster and curls his fingers inside you.
heeding his warning, you try clasping your legs together again. senku stops the attempt and immediately slams them back down.
”please!! wait!!” your muscles twitch. a blinding white pleasure takes over your body. chills wash over your skin as you let out a choke out sob.
licking his lips, senku releases his hold on you. he backs off smugly.
“i’d say that was around a seven. what do you think?” he reaches for the clipboard but you kick his arm.
“shut up.”
“hey, i need to record the data.” despite his tone, the smug smirk remained. senku stands and notes down the ‘data’. you notice his erection peeking through the lab coat.
“is that an erlenmeyer flask in your pocket, or are you excited to see me?”
eyes focused on writing, he states, “shut up. can’t help it. i’ve been wanting you forever.”
your face heats up at his confession, stomach doing backflips. you peek over at him. from behind the clipboard, a light red floods his cheeks.
“let me help you.” his hand freezes.
“how?”
gingerly, your jaw slacks open as you offer your mouth.
“shit.” senku drops the clipboard. he rips his lab coat off while basically leaping back onto the bed, stepping out of his tunic on the way.
fumbling with the rope, he quickly frees you.
you sit up so his crotch parallels your face. you gulp at the erection in front.
he nervously asks, “are you sure? once we start i don’t think i can stop.”
“take your fucking underwear off.”
he laughs under his breath and unveils himself.
thick. veiny. it’s pale with his mushroom tip angrily flushed. about seven inches? fuck. no, eight. how was he hiding all that under with that tacky e=mc2 tunic?
he slaps himself against your face and pushes his tip against your lips. “open.”
dropping your jaw he slowly pushes in. senku visibly shudders. he wraps his hand around the back of your head, fingers intertwining with your hair. you hollow your cheeks and swirl your tongue around his tip.
“fuck!” senku bucks his hips causing you to gag on the length. you bob your head rhythmically before he uses his grip on your head to push your mouth deeper onto him.
fully face fucking you now, he thrusts down your throat and forces your face to meet halfway. gag and saliva dripping down your jaw, you struggle with breaths in between his relentless thrusts.
you look up, eyes glossy with tears. senku groans above you. all of a sudden pulling out. you desperately gasp for air.
“don’t look at me like that. i just about embarrassed myself.” he shuffles to grab the condoms, ripping them open with haste.
you watch intently, dripping with anticipation. his length slapping against his toned stomach as he rolls the latex over it. he backs up, giving your clit a kiss before straightening his posture. he rubs his manhood along your folds, slathering it with your slick.
lining himself against your hole, he pushes. the rim of your entrance burns with the stretch.
strained, he coos, “baby, relax. i don’t wanna hurt you.”
you take deep breaths, trying to relax your walls. you feel every inch and every vein as he intrudes. once fully settled inside, you are left a twitching mess.
senku grabs the back of your knees, drawing your legs to your sides into a mating press. the new position allows senku to lean in close. still deep inside, he gingerly pecks the apples of your cheeks. licking the tears away he waits until you’ve adjusted.
lips locked again, senku passionately explores the caverns of your mouth. unconsciously, you start rolling your hips, causing senku’s breathing to stagger.
“seems like you’re ready.”
walls surrounding him, he starts pulsing in and out. your moans are muffled into his mouth. maintaining his rhythm, he pulls back from the kiss to stare at you, as if he were trying to engrave the memory into his mind.
legs wide. tear soaked cheeks. skin covered in rosy petal shaped hickies. angelic voice gracing him with a taste of heaven.
senku hits a particular spot within you that causes a long, choked wail.
“keep making those noises.” evidently affected by your state, he grows inside you. thicker. longer.
he moves his hands to the small of your back, forcing you to arch deeper into him. senku earnestly fucks that spongy spot inside you. he wasn’t just rutting into you. it was calculated. precise and intentional. your mind blanks as you reach your peak once again. noticing the signs, senku rubs circles into your overstimulated bundle of nerves.
cold washes over you. you let out soul wrecking moans.
your gummy walls shudder and twitch around him. “don’t squeeze me like that,” he strangles, “fuck, i’m close.”
his thrusts get irregular. faster. deeper. riding out your high, as he approaches his own. his grip around you tightens, accidentally digging crescents into your hips. panting as he pounds your abused cervix, he feels you go limp. sobbing while feeling more and more wrecked with every snap of his hip.
he gives one final thrust before finishing deep within you.
chest heaving, senku collapses above you; his face buried in your neck.
his lips curl against your skin, “i’d say that was like a 10.”
you groan.
“you don’t think so? well, every good experiment has trials.”
you feel a bulge grow on your stomach.
“GAH!!,” you shriek. “get away from me!”
a/n: this is my first fic! i spent like four days obsessing over it and might make it a hobby lol
germansingergirl
izzy806
amandla
yousharknotpass
gummygunk
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