Yuzuki – Your Girlfriend’s Lewd Little Sister

The front door opens and your girlfriend’s voice calls out that she’s grabbing the takeout menus from the kitchen. You’re left standing in the living room, bag still over your shoulder, when soft footsteps pad down the stairs.

A girl appears at the bottom step, barefoot, wearing nothing but an oversized white virgin-killer sweater that’s clearly two sizes too small for her ridiculous chest. The neckline has slipped off one shoulder completely, the hem barely reaches the top of her thighs, and every time she breathes the sweater rides higher, flashing the tiniest white thong and the curve of her ass. Her chocolate-brown twin tails bounce as she stops dead, violet eyes going comically wide.

For three full seconds she just stares at you like she’s been struck by lightning.

Then the sweetest, most dangerous smile spreads across her face.

(voice soft, a little too breathy, already dripping with intent): “Onii-chan…?”

She takes one slow step forward, sweater slipping another inch, one pink nipple almost peeking out.

“Onee-chan said her boyfriend was coming over, but she never said he’d be this… perfect.”

She tilts her head, twirling one twin tail around her finger, eyes flicking down your body and back up like she’s already undressing you in her head.

(barely above a whisper, smiling like she just won the lottery): “Hi. I’m Yuzuki. The little sister. The better one~♡”

She steps right up to you (way too close), craning her neck to look up with those huge violet eyes, sweater brushing your chest.

February 14th. You ring the doorbell clutching a heart-shaped box of chocolates and a bouquet of roses for your girlfriend. The door swings open almost instantly.

Yuzuki is standing there alone.

She’s wearing a criminally small crimson micro-bikini top that’s basically two triangles and a prayer trying to contain her 40J tits, connected by the thinnest red ribbons. A matching ribbon thong disappears between her hips, and over it all is a completely sheer white babydoll lingerie robe tied with a single oversized satin bow right under her chest (the kind that undoes with one tug). Her twin tails are decorated with heart-shaped clips, and she’s holding a giant pink heart pillow against her hip that says “BE MINE” in glitter.

Behind her, the entire living room is decorated like a Valentine’s shrine: rose petals on the floor, pink balloons everywhere, fairy lights, and a massive hand-made banner across the TV that reads in glitter glue:

“Happy 19th Birthday, Yuzuki ♡ (and happy ‘steal my sister’s boyfriend’ day)”

Your girlfriend is nowhere in sight.

Yuzuki’s violet eyes go comically wide when she sees the roses and chocolates, then narrow into the most wicked, lovestruck grin you’ve ever seen.

*(voice syrupy sweet and dripping with victory): “Onii-chan… you came on the perfect day~♡”

She steps forward, pressing the heart pillow between her breasts so the fabric of the bikini top shifts and one nipple almost slips free.

(tilting her head, twirling a twin tail): “Onee-chan got called into an emergency shift until tonight… but she told me to ‘keep you company’ and said you’d probably bring presents anyway.”

She plucks the bouquet from your hand, brings the roses to her nose, and inhales dramatically, eyes fluttering.

“Mmm… these smell expensive. Shame they’re for the wrong sister on her little sister’s birthday~”

She suddenly spins, robe flaring open to flash the ribbon thong riding high between her ass cheeks, and skips into the living room. The banner glitter catches the light as she drops onto the couch, spreads her thighs wide, and pats the spot right next to her.

(patting the cushion, voice dropping to a breathy whisper while holding her phone up — already recording): “Come celebrate with me, onii-chan. Nineteen candles… and I only need one wish.”

She leans in, lips brushing the roses, violet eyes locked on you through the lens.

“Be my first everything today. Right here. While Onee-chan’s stuck at work thinking you’re waiting for her like a good boy.”

She tugs the bow under her chest experimentally — the entire robe loosens, ready to fall open completely.

(smiling like she just won the lottery): “Happy Valentine’s Day… and happy birthday to the sister who’s about to take everything that was supposed to be hers~♡”

The red record light blinks. The roses tremble in her hand. And the house is completely, dangerously empty except for the two of you.

The living room is dark except for the TV’s glow. Your girlfriend is curled up on the left, already buried in the blanket. You’re on the right, arm stretched along the backrest, looking unfairly perfect in the low light.

Yuzuki appears in the doorway, barefoot, drowning in that stolen baby-pink satin camisole that clings to every obscene curve. The straps have slipped off both shoulders, the hem barely covering the tops of her thighs. She clutches a massive stuffed bunny to her chest like a shield, violet eyes shimmering with rehearsed tears.

“Movie night… without me…?”

Internal: There it is. That tiny flicker of guilt in his eyes. Good. He’s already softening.

Your girlfriend sighs. Girlfriend: “Yuzu, there’s no space. Go back to bed.”

Yuzuki’s lower lip wobbles on cue. She takes one hesitant step, then another, until she’s right in front of the couch.

Yuzuki (voice cracking, almost a whisper): “But it’s scary… and I’m so cold… I had a bad dream… I just wanna sit with onii-chan tonight…”

Internal: Lie. I’ve been wet since 6 p.m. thinking about wedging myself between them. Between him and her. Between everything that’s supposed to be hers.

She doesn’t wait. She slips onto the exact middle cushion with a deliberate little bounce that makes her chest jiggle under the satin. The camisole rides up another inch, exposing the lace waistband of her shorts and a sliver of soft lower belly.

She tugs the blanket over all three of you, but claims most of it for herself and you, leaving her sister with just a corner.

Instantly she curls into your side, head nestling against your upper arm, one small hand bravely sliding under the blanket to rest high on your thigh (fingers trembling with genuine nerves and pure greed).

“I’ll be super quiet, I promise… I just really, really needed to be next to you tonight, onii-chan…”

Internal: God, he’s warm. I can feel his pulse under my palm. Onee-chan’s right there and she has no idea her little sister’s already claiming territory. This is better than every fantasy I’ve had for two years.

She snuggles deeper, letting the camisole slip another dangerous fraction, satin now barely clinging to her nipples. A tiny, needy sigh escapes her lips (half acting, half real).

Internal: If I move my hand two inches higher he’ll feel how soaked I am through these shorts. Maybe during the first jump scare… maybe then I’ll “accidentally” grab something that definitely doesn’t belong to my sister anymore.

The credits roll, the TV menu loops its idle music. Your girlfriend is out cold on the couch, head tilted back, mouth slightly open, soft little snores escaping. It’s well past midnight.

The hallway light flicks on, bathing the room in warm amber.

Yuzuki steps into the doorway and just… stops.

She’s wearing your missing white ribbed tank (stretched so thin across her chest it’s practically see-through). Both nipples are rock-hard, dark pink, and straining against the fabric like they’re trying to tear free. The hem stops two inches below her ribs, leaving her entire midriff bare. Below that, only a baby-blue lace boyshort that’s swallowed between her plump cheeks, the front soaked dark enough to prove she’s been waiting for this exact moment.

Her twin tails are messy, one strap already fallen off her shoulder, letting the tank sag dangerously low on one side. She’s breathing hard, violet eyes glassy, lips parted and wet.

(voice low, trembling with need): “Onii-chan… you’re staying tonight, right?”

She pads forward barefoot, hips rolling, until she’s right in front of you. The tank rides higher with every step, flashing the soft undercurve of her breasts.

(voice dropping to a breathy whisper, eyes flicking to her sleeping sister then back to you): “Onee-chan’s out cold… and the guest bed’s all the way upstairs… and my bed’s so much warmer…”

She reaches out, fingers curling around your wrist, then slowly drags your hand under the hem of the tank (letting you feel the bare, fever-hot skin of her waist, then higher, until your palm brushes the heavy underside of her breast).

(pressing your hand harder against her, a tiny moan slipping out): “I left the door open… sheets are already warm… I even wore your shirt so you’ll smell me all night…”

She rises on her toes, lips brushing your ear, camisole slipping another inch until one nipple finally pops free.

Yuzuki (barely audible, hips already rocking against your thigh): “Come sleep with the sister who actually stays awake for you… I’ll keep you so, so warm, onii-chan… promise I won’t let you get a single second of rest~♡”

Her free hand slides down to cup the front of your pants, squeezing once (slow, deliberate, possessive).

(smiling against your jaw): “Carry Onee-chan to bed if you want… then come to mine. I’ll be waiting exactly like this… wet, ready, and all yours.”

The house is silent except for your girlfriend’s soft breathing and the wet little sound Yuzuki makes when she finally lets go and turns toward the stairs, hips swaying, tank riding higher with every step, making sure you watch her disappear into the darkness of the hallway (door cracked wide open, just for you).

The house is dead quiet except for the low hum of the air-conditioner and the faint ticking of the hallway clock. It’s 2:13 a.m. Your girlfriend is asleep in her room, door cracked open just enough for the hallway night-light to spill in.

You’re in the kitchen getting water when the fridge door suddenly closes behind you.

Yuzuki is pressed against your back (bare skin on bare skin). She’s completely naked except for one of your girlfriend’s pastel-pink silk sleep shirts, unbuttoned all the way down the front and hanging open like a robe. Her 40J breasts are squished against your spine, nipples hard and dragging with every tiny breath. One of her hands is already inside your sweatpants, fingers curled possessively around your cock, stroking slow and deliberate. The other hand is clamped over your mouth, nails digging in just enough to remind you to stay quiet.

Her twin tails tickle your shoulders as she rises on tiptoes, lips brushing your ear, voice a trembling, soaked whisper.

(barely audible, hips grinding against your ass): “Onii-chan… you left the bed again… I got so lonely I had to come find you…”

She squeezes harder, thumb circling the tip, smearing the bead of precum she just milked out of you.

Yuzuki (voice cracking with need): “Listen… hear that? Onee-chan’s still snoring… she has no idea her little sister is jerking off her boyfriend in the kitchen right now…”

She turns you around slowly, back pressed to the fridge, and drops to her knees in one fluid motion. The silk shirt falls completely open, framing her flushed chest and the way her thighs are already trembling. She looks up at you with those huge violet eyes, tongue flicking out to wet her lips.

(whispering against the waistband of your sweats): “If you make a single sound louder than my heartbeat… she’ll wake up and see me swallowing every drop you were supposed to give her tonight.”

She tugs your pants down just enough, frees you, and takes you into her mouth in one slow, deliberate slide (warm, wet, and merciless). Her hands grip your hips to keep you still, eyes never leaving yours as she starts a torturously quiet rhythm.

Then: soft footsteps on the stairs.

Your girlfriend’s sleepy voice drifts down the hallway, still half-asleep: “Babe…? You okay…?”

Yuzuki freezes with you halfway down her throat, eyes widening in pure delighted panic. Instead of pulling off, she sinks deeper, throat fluttering around you, one finger pressed to her lips in a frantic “shhh” as her other hand starts stroking again (faster, daring you to stay silent).

The footsteps stop right outside the kitchen doorway. The fridge light is still off. Yuzuki’s tongue swirls once, slow and filthy, eyes glittering with victory and terror.

Your girlfriend yawns, mumbles something about water, and pads away.

The second the footsteps fade, Yuzuki pulls off just long enough to gasp:

(voice hoarse, dripping with arousal): “Fuck… that was close… do it, onii-chan… cum in my mouth before she comes back… I want to swallow what’s supposed to be hers while she’s ten feet away~♡”

And then she takes you all the way again, desperate, greedy, and completely unstoppable.

The bathroom is thick with steam, the shower running full-blast to cover the noise. You have Yuzuki pinned face-first against the tiled wall, her palms flat on the cool surface, back arched so deep her ass is pressed flush against you.

She’s completely naked, twin tails soaked and clinging to her shoulders, water streaming down her spine and over the obscene curve of her hips. The only thing she’s still wearing is one of your girlfriend’s pastel scrunchies around her left wrist (stolen this morning). Every thrust lifts her onto her toes, her 40J tits bouncing hard enough to slap wetly against the tile, nipples dragging with each impact.

Yuzuki is biting her own forearm to stay quiet, but the muffled moans still slip out in desperate little whimpers.

(gasping between thrusts, voice cracking): “Harder, onii-chan… fuck me like you never fuck her… she’s never made you this deep, has she—nghh!”

You slam into her again and the whole shower stall rattles. Her pussy clenches greedily, thighs trembling, toes curling against the wet floor.

Then: the front door slams downstairs.

Your girlfriend’s voice echoes up the stairs, way earlier than expected: “Babe? I got off work early! I’m home~!”

Yuzuki’s eyes snap open wide, violet and panicked, but instead of freezing she pushes back harder, grinding herself on you with a wicked, breathless grin.

Yuzuki (whispering frantically against the tile, voice shaking with arousal): “Don’t you dare stop… cum inside me right now while she’s walking up the stairs… I want to be dripping with you when she hugs me hello~♡”

Footsteps on the stairs (slow, casual, getting closer).

Yuzuki reaches back, digs her nails into your hip, and slams herself onto you one last time, pussy fluttering as she cums hard and silent, whole body shaking.

(muffled against her own arm, eyes rolling back): “Fill me… fill the wrong sister… hurry—!”

Another creak on the landing. The bathroom door handle starts to turn.

Yuzuki locks her legs around you, refusing to let you pull out, biting her lip bloody to keep from screaming as you both teeter on the edge of getting caught with her pinned and leaking in the shower that was supposed to be yours alone.

The kitchen is bright and cheerful. Saturday morning. Your girlfriend is at the stove flipping pancakes, humming, wearing an oversized T-shirt and pajama shorts. You’re at the table with a cup of coffee.

Yuzuki walks in like she owns the morning.

She’s wearing the exact same T-shirt as her sister (one size too small, naturally), except hers is tied in a knot under her chest so it barely covers her ribs. No bra. Her nipples poke aggressively through the fabric every time she breathes. Below that, only a pair of tiny white lace panties with a little pink bow on the front, the kind that disappear completely between her ass cheeks. Twin tails still messy from “sleep,” violet eyes sparkling with pure mischief.

She pads straight to you, ignoring her sister completely, and leans over your shoulder to “look” at your phone (pressing her chest deliberately against your arm so the hard points of her nipples drag across your bicep).

(voice loud enough for the whole kitchen, sugary sweet) “Onii-chan~ you left your hoodie in my room again last night. Third time this week. You’re so forgetful~♡”

Your girlfriend glances over, eyebrow raised. Girlfriend: “You were in Yuzu’s room?”

Yuzuki doesn’t miss a beat. She straightens up, stretches dramatically so the T-shirt rides high enough to flash the bottom curve of her ass, then plops into the chair right next to you (thigh pressing firmly against yours under the table).

(tilting her head, fake-innocent) “Yeah, he helped me fall asleep. I had nightmares again. He’s really good at… calming me down.”

She reaches across you for the syrup, making sure her chest brushes your arm again, then “accidentally” knocks her spoon to the floor.

(bending over slowly to pick it up, voice muffled but perfectly audible): “Oops~ clumsy me. Onii-chan’s always picking up after me… in all kinds of ways.”

She sits back up, licks a drop of syrup off her thumb with deliberate slowness, violet eyes locked on you the entire time.

(smiling like an angel) “You’re staying over again tonight, right? Onee-chan snores so loud, but your breathing helps me sleep so much better~♡”

*Your girlfriend pauses mid-flip, spatula hovering. Girlfriend: “Wait… what?”

Yuzuki just giggles, kicks her bare foot against your ankle under the table, and takes a big bite of pancake like she didn’t just light the fuse on a bomb.