Chapter Text
"I'm home!" I shout, stepping inside. Being back home after my first year of college feels weird. A strange mix of familiarity and distance, almost like stepping through time into the past. Being gone for eight months or so shouldn't be enough to make me feel nostalgic, dammit.
A series of thumping noises approaches rapidly after my announcement. "Derek!" A scrawny black-haired missile impacts my midsection, wrapping her arms around me. "You came back!"
"Of course I did," I chuckle, hugging Leah back. "Had to see how much taller you got, squirt."
Leah leans back to stare up at me seriously with her blue eyes. "I'm a teenager now," she announces imperiously, her ponytail bobbing behind her.
"You're eleven."
"That counts," she insists. "Everybody says it like 'teens' and 'twenties' and 'thirties'. They don't say 'tens'," she explains slowly and deliberately. "That's why I'm a teenager now. It's process of elimination."
"If you say so," I say indulgently.
She huffs at me and releases me from her hug. Leah's definitely started hitting her growth spurt, something highlighted clearly by the fact that she's dressed for soccer practice. Her uniform still technically fits, but is definitely edging toward too small, and only emphasizes that she currently suffers from the lanky look of a kid whose body hasn't properly adjusted to its new height, that awkward phase of being clearly no longer a child, but not actually a teenager yet.
A second set of rather more sedate footfalls come to a stop at the door. "Oh, it's you," Christine--or Chris, since she hit her moody teenage phase--says. "'sup, D-bag?"
"Chris! Don't be rude," Leah says. "I'll tell Mom you said that."
Chris rolls her eyes. "Mom barely has time to complain about everything I already do wrong, she definitely doesn't have time to care about my fuckin' language as well, kiddo."
Leah levels a disapproving glare at her older sister. It's actually fairly impressive for an eleven-year-old, but Chris just ignores her.
"Mom's been a real nightmare since you left, ya know?" Chris says to me, running a hand through her bleach-streaked chin-length hair. "Always getting on my case now that her favorite well-behaved son isn't around. I just got my license and she won't even let me go anywhere by myself or hang out with anyone. You totally owe me."
"'Anyone' meaning my friends that you always followed around being annoying?" I say. Because it's not like there's any reason Mom wouldn't want her rebellious high schooler daughter hanging out with a bunch of college-age guys or anything.
"Hey! They never minded having me around."
"Yeah, 'cuz you used to be a cute kid who wasn't 'annoying like all the other girls'," I say, with finger quotes included. "Dunno if you noticed, but you aren't a little kid anymore."
...to be honest, I'm sure everyone has long since noticed that cute little Christine isn't so little anymore, even my friends. Especially my friends, given Chris's fondness for ripped-up jeans and midriff-baring shirts, not to mention her stubborn tendency to 'forget' her bra when she first started developing a chest, or at home in general even if my friends were over. Or the time she came out of the shower in just a loosely-wrapped towel and nearly gave a bunch of high school boys an eyeful of middle schooler tits.
Not that any of my friends ever actually tried anything with her, since they all knew damn well I'd kick their asses for it, but I know they did a lot of looking. I certainly would have, if she weren't my sister.
"Hey! No arguing allowed," Leah declares. "Derek just got back. You can argue about dumb things later. This is happy time."
"Hm. I guess Mom's still at work?" I ask.
Leah heaves an exaggerated sigh. "Yeaaaah. Working late, again," she says. "Maybe if Chris wasn't a lazy bum and got a job it would help. I would, if I was 16 like her."
"Oi, dial it back there, runt," Chris says dismissively. "There'll be plenty of time for soul-crushing employment when we're boring adults. I intend to enjoy being irresponsible as long as I can get away with it."
Leah huffs and looks away, nose in the air. "Grow up," she says.
"Big words from a little kid," Chris snickers.
"Hey, lay off," I say. "It's almost dinner. If Mom's still working now she's probably gonna be really late, so why don't we take my car and go grab some fast food for dinner? I have some spare cash from my campus job."
"Can we?!" Leah says, eyes shining.
"Ha! Dibs on the front seat," Chris says, bolting for the front door.
"H-hey, wait! No fair!"
As I expected, Mom gets home late that evening and only manages to give me a "glad you made it back safely" before trudging off to sleep. I know being a single mom is tough and all, but geez. Chris vanishes into her room as soon as Mom is gone, leaving me to gently bundle Leah off to bed.
As I unpack my luggage, an unassuming bottle catches my eye. There's some incomprehensible science gibberish scrawled on the label, and under that a sticker that says, simply, 'take 1/day & allow 6 days for full effect & discontinue if unexpected results. WARNING: side effects likely permanent w/ diminishing potency'. Inside is a pile of hundreds of small, unlabeled white pills.
It's something I was given by a very sketchy friend named Tom, a science major of some sort who was involved in clinical trials for what was intended to be male contraceptive, and did in fact work, but had... problematic... side effects.
To be blunt, the drug also made the user's semen addictive. Extremely so. The official trials were discontinued once the complication came to light and the whole thing hushed up as an embarrassment, but apparently a group of people had managed to smuggle out a copy of the synthesis method and decided to conduct some very unofficial and very unsanctioned 'informal' clinical trials. I'm pretty sure they're aiming to sell this stuff on the black market somewhere, but the less I know the better in that regard.
All I do know is that my sketchy friend gave me a bottle of equally-sketchy pills, explained what they do, and strongly encouraged me to try them and report back on the results. I'm somewhat reluctant to do so, though mostly just because the idea of Tom sitting there with his weird mustache and squinty eyes taking notes on my sex life is vaguely horrifying to contemplate.
If I'm honest with myself, there's a dark part of me that relishes the idea of an attractive girl being utterly dependent on me. Hell, on my dick specifically. According to Tom, while the actively addictive properties wear off pretty quickly without taking more pills, the addiction itself seems likely to be very long-lasting, and something that only the man who caused the addiction will ever be able to satisfy.
I've heard enough stories about the lengths junkies will go to for a fix, even when the side-effects are horrible and they're actively killing themselves in the process. To have someone in that condition, with absolutely no harmful side effects and with yourself as the only possible provider? The sheer power that would give you over the victim is alluring, intoxicatingly so. Anyone would be tempted, if given the opportunity.
I shake my head and violently shove the pills into the back of a drawer, but my mind is already wandering to the possibilities. I sit on the edge of my bed as I imagine the faces of various female classmates, from the cute girl I once sat next to in high school English class to my hot lab partner in college gen ed chemistry, all on their knees and begging with sorrowful eyes for just a taste of my cum...
My door abruptly opens. "Yo, things got quiet in here, you--whoa?!" Chris stops short, eyes wide, as she catches me with my hand in my pants blatantly masturbating.
"Chris--!" I growl, wiping my hand off and doing my pants up.
She just laughs. "D-Man whippin' out the D, huh?" she says teasingly. "What's the matter? Missing all that hot ass you're totally getting at college? Or just so pent-up you can't handle sharing a house with a hot chick?" She pushes her chest out a bit, and laughs again at my glare.
"Dammit, Christine, don't go barging into my room without warning!" I growl. "You wouldn't like it if I did it to you, would you?"
"Nah. Sorry, bro, but I'm just not into you that way," she says.
I just rub my face in frustration. I love Chris, don't get me wrong, but she's always been kinda bratty and determined to stick her nose in where it doesn't belong. And that was before; in just the half a day I've been back home she's been twice again as clingy and invasive as before. Fighting with Leah over sitting up front with me, stealing half my fries at dinner, grabbing my arm and dragging me around for no reason, just constant minor stuff. It's nice that she missed me, but there's a point where it's too much.
"Whatever," I sigh. "What did you want, anyway?"
She spins my desk chair around and flops down in it. "How'd you like to do a huge favor for your favorite sister?" she says.
"Oh really? What does Leah need?" I ask acidly.
Chris puts a hand to her chest and flops her head back. "Ow! Right through the heart," she moans, then sits back up. "Come on, bro, you still owe me for putting up with Mom being such a terror."
I roll my eyes. "What do you want?"
"Well, to start with, you can take me shopping," she says. "It's already summer and I still don't have a swimsuit, but Mom's too busy to take me and won't let me go alone."
"Okay, sure," I say. "We'll hit the mall like old times, laugh at all the fussy and uptight old farts and dunk on dumb fashion trends and eat sugary crap and buy things we don't need."
"Fuckin' A," she says, bouncing to her feet. And bouncing a bit in other ways, as much as I try not to notice.
"Just... calm down a bit, will you?" I say, exasperated. "I missed you guys too, but come on."
"Yeah, yeah, whatever," she says, waving a hand as she leaves.
Hanging out at the mall is fun, but unfortunately it doesn't really help. Chris continues to pester me at every available opportunity, to the point that even Leah starts giving her shit about it. I especially find myself lamenting that Mom never let us have locks on our bedroom doors, because after walking in on me handling my cock Chris seems to be taking a petty, almost malicious delight in barging into my room without warning at all hours, either to talk at me if I'm available or to mess with my stuff if I'm busy or not around.
I get a little nervous about her finding the sketchy mystery pills, so I hide the bottle behind a bunch of textbooks, something I know she'll be actively uninterested in.
I'm mildly annoyed when she borrows my handheld game console without asking, and exasperated when she appropriates a jacket with the excuse that it's 'too cool' for me, and losing patience when she accidentally knocks over a stack of formerly-organized school papers, but the final straw is, of all things, when I'm showering and notice my embarrassingly-expensive body wash seems to be running out a lot faster than it should.
"Come on, bro, Sharing is caring, innit?" she says when I confront her. "You can use my stuff if you want! It's, like, sibling bonding or something."
I rub my face in frustration. "Okay. Whatever. Fine. I don't even care anymore," I grumble, stomping back to my room.
It doesn't help that with her invading my room constantly the morning shower is the only time I can blow off some steam, by which I mean masturbate, and even then someone starts yelling about not using up all the hot water if I don't rush things. Being put in a foul mood managed to ruin even that one bit of release, leaving me feeling wound-up and frustrated in multiple ways the entire day.
I start rearranging my stuff that evening, partly for something physical to do and partly because Chris made a mess again. Is it really that much to ask that she be even a bit less clingy? What the hell would it take to get her to actually do what I tell her to?
--and just as I think that, my eyes happen to stop on the bottle of pills.
It's wrong. I know it's wrong. But in that moment, my thoughts focused on my annoying sister, I find it very hard to care. My mind turns to memories of trying to ignore the way her tits bounce and how her ass looks in a swimsuit, and to imagining her kneeling, obedient to my every whim. If she's going to be clingy and give me no privacy anyway, why the fuck shouldn't I at least enjoy it? Right?
Before I can have second thoughts, I twist open the bottle and down a pill.
Over the next few days, as Chris continues to be as annoying as before, I channel all my frustrations into staying on the path I've chosen. One pill every evening and, after waiting for them to start having an effect, hastily jerking off into the dregs of the 'shared' body wash while showering in the morning.
At first I don't notice any changes, other than Chris getting a bit physically clingier and spending an odd amount of time staring at me. It's only a week later, after the body wash has run out, that the effects become obvious.
"Come on, Derek," Chris whines. "Don't you have any more?"
"No," I say. "You used it up."
"Then buy some more!"
"Buy your own."
"...ugh, whatever. Drive me to the store, at least?"
"Sure," I say.
Needless to say, it doesn't help, and Chris becomes visibly distressed over the following days. She eventually demands to know what was different about the previous bottle of body wash I had... so, I tell her.
"Ah, I jacked off into it," I say. "To get back at you for stealing it, you know."
Her face twists in disgust. "Ugh?! That's gross," she says, recoiling. "You're joking, right?"
"Nope. But if you ask nicely, I might donate some more if you liked it that much."
She twitches and hesitates, as if seriously considering it, before shaking her head vigorously. "Wh--what the hell, Derek! You're disgusting!" She stomps away, angry.
Now that she's obviously hooked, I stop worrying about her invading my room as long as everyone else is asleep, and so a day later Chris barges in on me masturbating again, this time just as I finish.
She freezes briefly, transfixed, and then slowly walks toward me in a daze.
I swipe a blob of cum onto one finger and wave it in front of her face. "Looking for this?" I ask.
She practically lunges forward, grabs my hand and sucks on my finger, the tension in her shoulders relaxes slightly... and then she freezes again as she realizes what she just did.
Chris pushes me away, looking ill.
"Feeling better already, are you?" I ask. "It's even more effective internally than just rubbed on the skin, you know."
"I--" she looks disgusted and confused in equal measure.
"I'm pretty sure I've got another load in me if you're that desperate."
She visibly trembles with emotion before slumping in surrender. "...I... I am."
"Then, help yourself."
"What?!"
"You're 16, Chris, I'm sure you know what a dick is," I say. "You want more, come get it."
Expression furious, she leans down and makes a reluctant, halting attempt at a handjob. Her motions are stiff and mechanical, clearly forced, but she manages to coax an erection out of me nevertheless even despite the fact that I just came not even two minutes ago. I'm starting to suspect that increased libido and semen production are another side effect of the pills, and sigh internally at the fact I'll probably have to tell Tom about it.
Unfortunately, after getting me hard she doesn't really make much progress. "You're terrible at this," I say.
"Well, what do you expect?" she snaps, angry. "It's not like I've done this before! And you're my brother! It's gross. You're gross. Why the hell are you making me do this?"
"Because you wanted to," I tell her, well aware that she really doesn't want to. "If you want to stop, you can." If only addiction was that easy to ignore.
She just growls at me.
After another couple minutes of her being ineffective, I sigh and put my hand on her shoulder and push her away. "Yeah, this isn't working," I say, then give her a considering look. "Try it with your mouth instead."
She recoils. "What? No!" she hisses angrily. "I'm not giving you a fucking blow job, Derek!"
"Then I guess we're done here."
"That--" She looks lost for a moment, before screwing her face up in disgusted fury. "Yeah! We are," she says, and leaves--surreptitiously licking her hand as she does, to get every last trace of me into her.
Her resolve lasts longer than I expected, even as the temporary reprieve from the small taste she got wears off. She gets increasingly irritable and lethargic to the point that even Leah is clearly worried about her, but Chris avoids me for the most part. She does sneak into my room a couple times when I'm not there, apparently to go through my trash. I don't know if she's looking for used tissues from when I masturbate or what, but I've been taking great care to dispose of those safely so it's not like she's finding anything.
After a few days of ignoring me, she flips over to being passive-aggressive and snippy with me, which gets tiresome real fast, and is even enough for Mom to notice and lecture her about.
After a full week of withdrawal, things come to a head. Chris looks like death warmed over as she barely manages to drag herself out of bed in the morning even with Mom's shouting, she has no appetite, and is clearly unwell. She shoots resentful but increasingly contemplative glances at me throughout the day, but makes no effort to approach me when we're alone.
Eventually, Chris staggers off to bed, looking tired and ill enough that even mom doesn't insist she help with cleaning. Leah obediently drags a stool over to help me with the dishes, whereupon we flick soap suds at each other laughingly until mom yells for us to stop dawdling and get to work.
Once all the evening chores are done Mom hustles Leah off to bed and then prepares to get some sleep herself right after--though not without stopping to lecture me on not staying up late just because I'm in college now and how I'm an adult now and need to be responsible (which is true) and how being on break is no reason to ruin my sleep schedule and how college professors won't put up with anything other than punctual attendance (which is definitely not true, they don't give a shit unless you disrupt a lecture) and so on until she finally runs out of things to nitpick and nag over and goes to sleep.
I love my mother, I really do, but sometimes she just needs to chill.
Later that night, after spending an hour or two reading to be sure mom is asleep, I step out of my room dressed in just my sleep shirt and boxers and pad down the hall to Chris's room. Her door is closed, so I open it carefully and slip inside.
Chris is shifting restlessly on top of sweaty sheets, having kicked everything else to the floor. The T-shirt she sleeps in clings to her body, outlining the curve of her breasts and the very obvious peaks of her nipples, and has ridden up high enough from her movements to reveal her toned thighs and a bit of her panties.
I put a hand on her thigh and she startles awake almost immediately. She blinks up at me. "De--" she begins, but I immediately put my hand over her mouth when she starts to speak.
"Shh. Make too much noise and I'll leave," I say.
I remove my hand and she nods feverishly. "P-please, I need it, I need more," she whispers frantically. "I'm sorry I didn't do a good job, I'll do better, I'll give you a blow job now, I--"
I wonder, just how far can I push this...? I shake my head. "You had your chance," I say.
"B-but--!"
"If you want more now, you have to let me use your face."
She flinches back. "U-use...? Like..." she trails off, reluctant.
"Okay. If you're not interested..." I start to leave, but her hand snaps out and grabs my arm.
"No!" she whispers forcefully. "It's... do whatever you have to, okay?"
"Hm. Okay," I say. I abruptly grab a leg and yank, twisting Chris around and pulling her lower body off the bed. She bites back a cry of surprise as she slides half onto the floor, leaving her kneeling while leaning back against the side of her bed, eyes wide.
I tug down my boxers with one hand while pushing her head back against the bed with the other. She cringes slightly, but doesn't resist as I step forward, straddling her body, and lean over her. "Mouth open," I order. She obliges, looking both desperate and fearful, and I shove my cock into her mouth and down her throat.
Chris screws her eyes shut, tears in the corners, as I thrust repeatedly down into her mouth, her head bouncing slightly against the mattress. Just having my cock inside her seems to take the edge off the cravings, though, and she gradually slumps weakly against the bed, visibly relaxing even as I aggressively fuck her face.
I grab her hair as I begin to thrust harder, and she moans and writhes under me, her initial reluctance and distaste quickly fading into a passive, unresisting contentment. Eventually, she even reaches up to grab my hips and greedily draw me back in every time I pull out to let her breathe.
I finish in short order, thrusting in as far as I can until her face is pressed into my crotch and spurting ropes of hot cum directly into her throat. She swallows hungrily, as desperate as a starving animal given food. Once I finish and pull out she looks dazed and euphoric for a few seconds, before suddenly leaning forward to wrap her arms around my hips in a hug.
"Thank you, Derek, thank you, thank you," she mumbles, nuzzling her face into my crotch. "You're the best brother ever."
I rest my hand on her head possessively. "I am. It's good that you realize that." Even if it's my sister instead of the classmates I'd initially imagined, the reality is so much better than the fantasy.
For the next couple days, Chris is back to normal. Which, unfortunately, includes arguing with Leah and hassling me constantly. If anything, she seems to be acting out even more in some sort of effort to monopolize my attention.
After getting fed up with her behavior, I pull her aside. "If you really want my personal attention," I whisper into her ear, arm around her shoulders, "you just need to wait until we're alone."
She shivers involuntarily, then shoves me away. "Whatever," she mutters, with classic teenage petulance.
The withdrawal starts kicking back in after a couple more days, but Chris's behavior doesn't really change much. She corners me in the afternoon, while Mom is at work and Leah is at soccer practice, already looking twitchy and anxious.
"Derek," she whines quietly, shuffling closer to me. "I need more."
I just hum noncommittally, turning the page in my book.
"Derek...!"
"What's the magic word?" I say, smirking.
She lets out a strained breath. "Are you seriously pulling that?"
"That wasn't the magic word."
"Dammit!" she hisses.
"Neither was that."
"Ugh. Okay, fine. Derek, can I please have more?" she says flatly.
"Hmm," I say, setting my book aside. "Nope. Not good enough," I say.
A flicker of desperation passes over her face as I stare her down impassively.
I smirk slightly. "Beg for it."
"What?! The hell does that mean?"
"You've been bratty and disobedient all week even when you're asking me for favors. You need to understand who's in charge here," I say firmly. "Hands and knees. Promise to do as I say and beg me to gift you my cum. Then I'll consider it."
"I--" She starts to make halting movements to kneel, her face flush with embarrassment, before her pride manages to win out over the withdrawal and she surges back up to her feet. "No! I'm not playing this stupid game, Derek."
"...your loss," I say, and go back to my book. She tries to argue further, but I ignore her.
Chris's behavior becomes increasingly erratic, jumping between her usual brattiness and desperate, longing obedience, until her resistance finally breaks two days later. Even as she struggles to conceal how awful she feels from Mom and Leah, she's outright deferential to me in an extremely gratifying way. So much so that I find myself imagining how nice it would be to get the same treatment from Mom, or cute little Leah...
Chris sneaks into my room that night, while I'm still up using my laptop but after Mom and Leah are asleep. The withdrawal is getting really bad at this point; she looks feverish and her hands are shaking.
I look up at her. "Yes...?"
She takes a shuddering breath, closes her eyes, and gets down on her hands and knees. "Please, Derek. I'll be good. I'll do as you say. Anything you want," she says, voice shaky. "Just please, please, I'm begging you, please, let me have more."
"More what?" I say.
She fights back a scowl. "Please let me have more of your cum, Derek."
"Good girl," I say, leaning forward and ruffling her hair. "Of course you can have more."
She sighs in relief and looks up at me in anticipation, mouth open.
"...but I'm afraid choices have consequences, so we'll be doing it a little differently this time."
"Okay...?"
"First, strip."
Chris bites her lip, hesitating for a moment, then reluctantly complies. She quickly pulls off her pajamas, leaving her in just panties, then hesitates again. Her face is burning with humiliation as she bends over and pulls her panties down.
I very obviously look her over. At this point I really might as well admit it: My sister is hot. Thin, but still curvy enough, average-sized but delightfully perky tits with small pink nipples, a flat stomach, smooth, slender legs, and pubes trimmed into a tidy racing strip.
She whines slightly as I look her over, so I gesture her across the room. "On my bed--ah, no," I say, as she sits on the edge. "Lie down. On your stomach."
"But how..." she protests, even as she moves to obey, but falls silent at a stern look.
I grab a spare pillow and climb onto the bed with her. "Lift your hips," I command, and slip the pillow underneath when she does, leaving her face down with her backside raised and pussy exposed.
"Derek...?" she whispers fearfully.
"When I said it would be more effective internally, I didn't just mean swallowing," I say, as I start pulling my clothing off.
She inhales sharply. "B-but--!"
"Don't worry, I'm using some experimental pills that make me temporarily sterile."
She whimpers slightly. "Are you really going to..."
"Do you want this or not?" I ask, kneeling behind her.
"I, I mean... I--" she stutters.
"Yes or no, Christine."
"...yes," she chokes out.
"Good girl," I say warmly, and slide my dick into her.
She yelps in shock, then buries her face in my pillow to muffle her strangled cries as I push deeper. Her insides clench around me and her hands grab my bedsheets in a white-knuckled grip. She moans quietly as I begin thrusting, plunging deeper with each movement as I slowly stretch her virgin pussy to accommodate me.
Once I find a pleasant rhythm I lower myself down, laying on top of her, gently stroking her hair with one hand as I fuck her. "See, Chris? Isn't it so much easier when you just do what I say?"
She whimpers and nods as my weight presses her down into the bed, pinning her in place. I can feel some of the tension in her muscles start to relax; even the small amounts of precum must be a potent relief for her at this point.
"I didn't enjoy having to cut you off, you know. But you needed to understand how things work," I say gently. "No more arguing from now on, okay?"
"I won't," she says in a quiet voice, barely audible over the sound of flesh slapping together as I pick up speed, pounding even harder into her.
"You're mine from now on, Chris," I say. I slide an arm around under her chest, cupping and squeezing one breast and pressing her soft body against me. She whimpers and moans incoherently. "No disobedience. No hiding. No boyfriends. Mine and mine alone."
"...'kay..."
With a final, violent thrust that makes the bedsprings squeak I come inside my sister. She lets out a sob of relief as the withdrawal finally fades fully, rolling over onto her back to catch her breath, leaving her fully exposed in the cool air. She pants heavily, a blissful expression on her face as her breasts bounce with each gasping breath.
But I find that there's still a knot of tension twisting inside me at the sight of her naked form sprawled across my bed. I'm not satisfied yet. This isn't enough. And if I've gone this far, really... what's a bit further?
I run my hands greedily over Chris's unresisting body, imagining all the other girls and women that could someday be in her place... and one girl in particular. I pull Chris's limp form into my arms, and she nuzzles weakly against me as I hold her. "...oh, and Chris?" I say quietly. "Starting tomorrow, I expect you to help me train Leah the same way. Okay?"
"Mmm. Anything you want, Derek," she murmurs in contentment.