#lemme know.

A sudden knock at your bedroom door startles you. You quickly alt-tab away from the transbian robot porn game to tumblr, something a little less innocuous, and pull up your shorts as you start towards the door. Moms were supposed to be gone for the day, what are they doing back? 

You get to the door, kicking a big plushie out of the way of the door, and open it up not to your moms, but to the surprising presence of your sister Catherine, dressed all stereotypically skaterpunk. She’s got a baggy long-sleeved shirt under a baggier hoodie with the sleeves cut off at the elbows. Black pants with metal studs running up the outside of each leg, and a chain going from her back belt-loop to her front pocket, undoubtedly attached to her Adventure Time wallet you got her when she turned 18. 

“Cat! Hi!” You half-shout in surprise.

“Hey Birdie, whatcha up to?” She reaches out, and ruffles your hair before pulling you into a hug that’s a tsunami of fabric against your face. You freeze a little, unsure of what to do with your hands considering what you were just doing, but after a second of half-hugging her back while keeping your hands up, you let yourself relax into a real hug, and squeeze her tight. You breathe in a deep sigh, and your lungs are filled with the comforting and familiar scent of your sister. You’ve missed it more than you realized. Maybe a little more than you should.

A twinge of guilt shoots through your chest, and you quickly let go of the hug, gently pushing away from Catherine. She lets go of you, and you look down at her shoes, unable to look her in the face

“I, uh, sorry, I’m not really doing anything right now?” you lie, though it doesn’t exactly hurt Cat to lie about the fact you were jerking off while playing a porn game. You impulsively start rubbing your hands against the fabric of your shorts. “W-what are you doing here? Aren’t you supposed to be at the dorms this weekend?”

“Yeeaah, but it’s so fucking boring. C’mon Birdie, grab your board, I’ll meet you outside.” She says before jogging down the carpeted stairs. You hear the front door open and close, and you run to grab your board from the wall by your closet and follow her lead.

You always liked skating with your sister. She got her first skateboard the summer she turned 14, and you were instantly in love with the activity. You watched her every day as she practiced riding around the smooth black-top of the one high school in town; the only place that could afford to do anything about the pot-hole riddled concrete that made up the entirety of the small midwest town. You begged Ma and Mom for a skateboard for your 13th birthday too. Come that fateful day at the very start of October, you come down-stairs to homemade raspberry cream cheese pancakes (Catherine’s special recipe) and a big box on the dining room table. 

You and your sister rode your boards to and from school every day together for 3 years, from 8th grade ‘til the end of Sophomore year when Catherine graduated. You enjoyed that last summer skating through town with her, savoring every moment knowing they’d be fewer and farther between from then on. 

The door closes behind you, board in hand, and you lock the door with your spare key before clipping your keys on the side belt-loop of your jean shorts.

“Awww, Birdie, that's an adorable board!” you hear her coo as you turn around. You blush, looking at the design you made and custom-ordered.

It’s a cloudy sunset of whites, pinks, and blues. Obvious with the color choices, but less tacky than your last board with the trans-flag lazily slapped on the bottom. Your moms were so sweet in their support, but stars, they have no taste. 

“Th-thanks Cat, um uh, its a custom job! I designed it myself actually.” You stammer out, embarrassed at the fact that you’re so easily embarrassed. It’s really a vicious cycle.

“No fucking way! Really? Robin, it's beautiful!” Her voice is filled with genuine awe. “How much did that thing cost?”

“Oh uh, I dunno. Moms covered it for me as a, um, birthday gift.”

“Heh, we lucked out with them didn’t we?” She sighs, and you notice her looking at the front of your childhood home with eyes full of happy memories. You see her eyes begin to sparkle as tears start welling. She even looks beautiful when she cries.

“Anyways!” she snaps her attention back to the road in front of your house, not a single car in sight in either direction, “C’mon, pretty girl, let’s get out of here,” she starts taking off down the sidewalk, running a few steps before dropping her board in front of her and effortlessly, no, elegantly, stepping on and pushing forward.

You take off after her, your board built more for speed than hers so you’ll catch up quick. The large, softer wheels and the bullet shape of your board are much more comfortable for you. You never cared about tricks, not like Cat, with her more traditional board, small hard wheels and normal shape. It’s exhilarating, the cool autumn wind flowing through your shoulder-length hair, unrestrained by anything. Your sister’s cap keeps her much longer, jet black hair out of her face. She kicks her board and does a simple ollie over the curb into the road, and turns. You know exactly where she’s going.

You kick the concrete harder, pushing your board faster and pass her by. She gets a shocked look on her face for half a second before a mischievous grin crosses her lips. 

“Race you there!” you call out, you know she can’t resist the challenge, and she kicks harder, willing herself faster. She’ll take the long route, that’s how you always did it back then. You only found the faster route with your new wheels, letting you go over cracked concrete easier. You take a turn, and then another one, cutting through the park.

The high school parking lot feels odd to be skating around during the school year, but the smooth blacktop feels so good under you as you glide along. You make a few slow circles on your board before you see Cat crest the hill from the long-way-round. You head towards one of the rubber-covered mesh wire tables that sit by the side entrance to the school. Purple, Cat’s favorite color. You eat lunch out here a lot, sometimes with friends, always thinking of her. Of her pretty face, of her smile, the way your chest flutters when you hear her laugh. Oh gods, her voice. Husky, yet absolutely a woman. It’s hard not to melt when she calls you that little nickname of yours she likes.

She looks almost ethereal skating towards you in the late afternoon sun; another hour or so till golden hour yet still amazing lighting on her. You pull your phone out, almost on instinct, and snap a few photos of her from across the parking lot. She starts waving, and you swap to video mode and hit record.

“Do a kickflip!” You shout, half-joking, half-hoping your attempt at goading her into a trick works. 

She kicks the board, and it spins in the air, with her landing back on it with a practiced grace. You can feel your heart in your neck, and your eyes open wider. You feel slight pressure against your jean shorts, but choose to ignore it. She’s laughing now, and getting closer. She abandons her board when she gets close, and throws herself at you into a hug. 

You and Cat tumble into the grass around the table, both laughing, playfully hitting each other. You try to lay on her to pin her to the ground, but you find yourself a whirl of limbs, the entire world doing a flip, and you find yourself pinned under her. Your sister’s chest pushing down into yours, her toes pushing into the ground hard, and an arm wrapped around your head and back of your neck. The pressure in your shorts gets even more noticeable, and your head is right at her hips.

Her shirts come up just enough for you to see a trail of dark hair from her belly button into her pants. It looks so incredible. You have to touch it, you need to feel it. You’re so close, you could just-

“EWWWW” Your sister scrambles off of you, laughing, “did you just lick my belly? That’s so gross!”

You blush hard, “Y-yeah, and?? Like you’ve never liked a hot girl’s stomach before.” You cross your arms and try to give a cute pout.

And then your sister does something you don’t expect. 

She starts blushing too.

“What? What hot girl would I lick? You know I’m single, and why would I like their stomach?” She asks, clearly at least a little flustered.

You shrug, “Tgirl tummies are cute, plus I’m sure you lick other parts too. There's gotta be tons of girls going wild over hot skater tgirls at college, right?”

Your sister stands up, brushing the grass off of her, and reaches a hand down to help you up. You take it, her hand is so soft, lanky fingers engulfing your smaller hands. She pulls you up to your feet, and pulls you into a hug, featuring a gentle noogie. 

“Ow, hey, quit it!” you squeak. She giggles, and lets you go.

“C’mon Birdie, follow me.” She starts walking towards the back of the school. You follow close behind, you and her both leaving your boards behind in the grass.

She doesn’t slow down for you, so you start jogging to catch up to her. You feel a bit strange being back here, you never had a reason for being behind the school before, except for that one fire drill last month when a gay freshman boy started flirting with you. Whatever, he’s just a stupid kid. You’ve been trying to not let it bother you since it happened.

You’re lost in thought when you feel your sister take your hand, winding your fingers between hers. You twitch, starting to pull away, and then pause. You let your hand ease back into hers. She stops suddenly, and your shoulder notices it before the rest of you does. The jolt to your body brings you back out of your thoughts. 

“Ever done this before?” she says, letting go of your hand. She starts walking towards the wall, pipes and gauges and ivy clinging to the brick.

“Done what?” the confusion in your voice matching that on your face. 

To your utter surprise, Cat starts running at the wall. Your sister jumps and grabs one of the pipes. She grunts as she pulls herself up, kicking at the wall. Cat finds a foothold. She lunges up, grabbing the ledge of the roof with one hand. She pushes herself up onto the roof, rolling just out of sight from you. You start forward while your sister’s head pops over the edge of the roof and looks down at you. 

“What the hell, Cat? Are you out of your mind?” You hiss up at her, you look over both your shoulders in quick succession to see if anyone’s around you. 

“It’s chill, I used to come up here and smoke all the time,” she reaches an arm down for you to take.

You grab it, and she helps pull you up. You’re definitely not as graceful as she is, but you make it up to the roof and roll next to her. You look into her eyes. They’re so full of life, those big, beautiful brown eyes of hers. Dark and shiny like polished wood, the same color as the black tiles of the chessboard you made in shop class last year. You wonder if she still has it in her dorm, you gave it to her as a present last winter. 

“Your eyes have so much more light in them now, you know that Birdie?” she asks calmly, almost like she’s being careful.

“Y-yeah. I, um, sorry it took me longer to realize I was a girl than you. Feels kinda dumb of me now,” you admit. You want to look away from her eyes but they have you under a spell. You can’t look away.

Your sister reaches a hand up and gently rubs the side of your face. “Don’t apologize. I’m glad I've got my baby sister now, that’s all that matters.” She pulls you in, and plants a kiss on your forehead. It lasts half a second longer than a platonic kiss should. Your heart starts to flutter harder than it has all day. 

After about 10 seconds, your sister sits up, and you take that as your cue to do the same, easily getting to your feet.

“So, is, um, this all you wanted to show me?” you ask, heart racing in your chest?

“This way,” She points ahead, and you follow her, walking to a ladder leading to a higher section of the roof, maybe above the gym?  Cat starts climbing the ladder, and you follow after her.

“There have been a few girls, but none that I was serious about. Nothing more than a few hookups, or some casual sex between friends. That kinda thing.” She calls down to you.

“What?” you’re confused again, something that seems to be a theme for today.

“You asked about the girls at college.” She keeps climbing, she’s not looking down at you. “There’ve been some, but nothing, like, emotionally fulfilling.” She crests over the ladder, and disappears from your view.

You pick your pace up, reaching the top quickly. Cat’s sitting on the edge of the roof straight across from you, legs dangling off the edge. You walk up to her, sit down next to her. Golden hour’s starting, and nothing has ever looked more divine in your entire life as your sister does in this moment. 

“So, what about you? Any girls here you like?” She’s looking out over the small town. You’re looking at her. It takes you a moment to realize you’re supposed to reply.

You sigh and lie back, staring up into the sparsely clouded sky. “No, no one here I like.”

“Here?” Your sister’s voice asks, and you hear her lay down beside you. You feel her knee against yours as you gently kick your legs back and forth over the edge.

“Mmm.” you hum out as a reply.

Very slowly, your sister speaks, “Well, what about, not here?” There's a bit of a scraping sound, and you can feel your sister’s shoulder against yours.

Your breath hitches slightly but you don’t mean for it to. “M-maybe. I, um, I don’t think she’d say yes though.”

“Why would anyone say no to such a beautiful woman?”

“Sh-she’d. She’s. I uh, I don’t, um. I don’t think she’d like me that way.” You sit up, and finally you take in the sight. It’s gorgeous. The town feels so small, despite not being that high up. You can see a few blocks away, down the hill the school sits atop of. You can see the park you skated through to get here. You pull your legs up, and wrap your arms around them.

You hear the shuffling of your sister’s clothes, and feel her arms wrap around your. She gently pulls you away from the ledge, and you scoot back with her. You turn and bury your face into her shoulder, letting her drown you in her arms. She smells so nice.

“Talk to me, Birdie. Why wouldn’t she like you that way?” Cat was pushing for answers. It feels like the edge of a knife. You could just tell her, get it over with and you two can move on and pretend this never happened.

“I’m not supposed to.” You croak.

“Not supposed to what, sweetie?” Her hand gently rubs your back. You’re fluttering again, the pressure in your crotch and behind your eyes growing in tandem. 

“I’m not supposed to like her like that. It’s, it’s wrong.” You’re barely holding back tears now. 

“Birdie, tell me why it’s wrong. Please.” She pulls away from the hug, grabbing your shoulders with both her hands. You let your head fall, you can’t bring yourself to look at her.

“Birdie, look at me, pretty girl. Please, look at me.” She gently moves her left hand under your chin, and carefully lifts your chin with her curled finger.

You can almost see a halo behind her, the golden light of the lowering sun shining right behind your big sister. You’ve never wanted anyone in your life more than you want her right now. The tears finally burst.

“I’m sorry Cat, I’m so so sorry, I’m gross I’m disgusting I’m sorry I am so sorry something’s wrong with me I’m horrible. I-I-I. I didn’t want to fall in love with you, I-”

Her lips meet yours in a flash, knocking you over onto the ground, her coming with you. Lips not breaking contact the entire time. Her lips are so soft, and they taste sweeter than ambrosia. This is heaven. She wants you too. Oh god, she wants you so badly. Her hands are running through your hair, feeling every inch. You reach up and grab her waist. Her waist is muscular, not too thin. She moans into your mouth. You pull her into you, hard.

Her lips part for a gasp, and your tongue finds its way into your big sister’s mouth without you even thinking. Her tongue swirls back with yours. It’s a dance of love and need and lust and fear. You’d been so scared for so long. The kiss breaks, and Cat stares down at you, her eyes sparkling with love and tears.

“You’re the most amazing woman in the world, Birdie,” She leans back and pulls you into a tight hug. “Never let someone tell you otherwise. You’re so fucking beautiful, Robin.”

You start blushing, your tears still burning on your cheeks. Your sobs are starting to calm, enough for you to get words out again. “I-I felt so dirty, for so long Catherine.”

“I know baby, I know,” She kisses your forehead gently. You feel a tug at your shirt, and you feel her warm hand against your waist. She squeezes, and you can’t help but moan. “Good girl, baby. Fuck, Birdie I need you. Please, my pretty bird.”

“C-Cat- aaaahh” the moan escapes , still nervous, but guilt washing away.

Her lips find yours again, her tongue performing a waltz of need and desire, your tongue its partner.

Your hands find their way all on their own to your sister’s body. You pull the hem of her layered shirts, reaching up, feeling her back, her sides, feeling the soft-as-velvet happy trail on her stomach. You start creeping higher, her skin softer than you could have ever dreamed.

Cat catches your hand and brings it up to her chest, squeezing herself with your hand. “Hmmmmf, fuck yes baby,” Lips breaking again, desperate gasps for air from you and her. “That’s it baby, feel up your big sister. Fuck, feel how big they’ve gotten.” She tosses her hat to the side, and grabs her baggy shirts and pulls them over her head. 

Your eyes and your hands taking in just how big your sister’s tits are now, her fashion choices definitely making it harder to tell. She’s huge, and firm in your hand as you start squeezing. Cat’s breath hitches, and you feel her hips bucking. She’s so beautiful.

“Hng, Cat, please Cat” You whimper, your sister’s grip on your waist tightens. She pulls herself closer, letting her wild hip bucking turn to more rhythmic grinding against your hips. Little moans escape from Cat’s throat, and you feel yourself get even harder against her hips. You can’t resist the impulse to start bucking your own hips against hers. You don’t want to resist the impulse. You need this, you need her, you need your big sister more than you’ve ever needed anything in your 18 years of life. 

Catherine’s grip shifts to your hoodie, the green and black striped zip-up she got you last year. She unzips it with blistering speed, and pulls it off of your shoulders. She chuckles, you’re wearing her old BLUE OYESTER CULT tee. “Aww, baby bird missed me? Fuck, did it smell like me?” You nod fervently, “It’s unreal how cute you are, Robin,” you don’t know how much harder you can blush, but it seems like your sister is going to find out.

One of her hands shoots back to your wild hips, controlling your them to thrust in time with hers. The other hand finds your chest, your tits so sensitive, and her soft hands squeeze with an amount of force you weren’t expecting. A deep, primal moan escapes from you. “Oh, FUCK!” are the only words that find their way out of your lips, and Cat dives back in for more kisses. Her hand finds its way under your shirt, and she starts feeling and squeezing your bare tit ( you rarely wear a bra). Your sister seems to appreciate that fact, you have that in common with her, apparently. 

She feels you and grinds into you and kisses you and eventually she breaks the kiss again. “Arms up, baby bird.” It’s not a request, she orders you. You’re being commanded by your sister. You comply, whimpering. She scoffs. “Good Birdie.” Your eyes flutter and you whine, fuck you’re being so pathetic. 

Your sister pulls your shirt gently over your head, and tosses it to the side. Her lips find your neck. She sucks, bites, kisses, everything you’ve ever imagined, every action you stayed awake till 4am fucking yourself over while drowining in guilt thinking about. She’s careful not to leave marks you can’t cover with your hair and your clothes, but she can’t resist marking you over and over and over again as her baby bird, her little sister, hers.

And then her lips find your nipples, and you cry out with intense pleasure you didn’t know was possible with your breasts. The flat of her tongue slowly scrapes across your hard nipple, and she smoothly transforms the lick into gentle sucking. She looks up into your eyes, hers full of adoration and hunger, and teases you with the tip of her tongue to create more suction. You buck your hips wildly again, ignoring your sister’s deliberate pace of thrusts.

She grabs your hand again, reminding you it’s okay to squeeze her too. You’re not sure when you stopped groping her back, it’s so much stimulus. It’s Elysium. Nirvana. Heaven. It’s bliss incarnate, and the muffled squeaks of pleasure that escape your sister’s lips from gaps of sucking and licking your chest make up the most beautiful symphony in the world. Nothing could ever compare to the sounds of your sister and you together like this. How could they? How could anything in all of creation sound as good as Her, and you get to be the one she makes those noises for.

“Cat, fuck, Cat I’m gonna-” you start grinding harder into her, desperate.

“Shhhhh, not yet baby bird, not yet.” She lets go of your breast with her mouth, and lifts herself off of you, just enough to reach down and undo your belt. With a click, the Invader Zim seatbelt style belt you bought at the mall 3 years ago with Catherine unlatches. Your sister’s hands easily undo your button and zipper, and slides your jean shorts down. Your simple white panties lie underneath the denim, and they’re soaked through with your pre. Your clit is hard, almost poking out the panties. With just one finger, Cat hooks around the waistband of your white panties, and gently pulls. 

Your clit pops up, the hardest it’s ever been since you started your injections a year ago. Your sister lets out something between a scoff and a chuckle, and you turn your head away. Her hand catches your chin, and gently guides your head back to face her. “Don’t look away from this baby. I want you to look at me while we do this, okay Robin?”

You nod, and her hand wraps around your clit. Your tip just just barely pokes out of the end of her hand. “Fuck, you’re so cute Birdie. You feel so fucking good in my hand.” She slowly pumps her hand, slicking across your clit with your leaking pre. Your voice catches in your throat, breathy squeaks the only sound that escapes. Your whole body tenses from the pleasure. 

Your sister lets go of you, and lifts her hips up slightly. She unbuckles her own belt with a click, a similar style to your own but with a yellow caution-tape design. She unbuttons and unzips her black pants, and you can see her dark blue boyshorts, bulging with her hard-on. She pulls her boyshorts down, and her dick pops up. It’s perfect. She’s several inches bigger than yours. You can’t help but giggle. 

“Aww, what’s so funny sweetie?” Your big sister coos as she lowers herself back onto your hips.

“You’re taller than, than me, um, an-and you’re bigger than me too,” you manage to half-moan the words out. 

Your sister scoffs and giggles in return. “You’re so fucking cute,” she says as she lines the head of her dick up with your clit. She warps her hands around the both of you, despite her being longer she’s not much girthier. You both fit comfortably in her one hand, still wetted with your precum. You feel yourself leaking out onto the tip of your big sister’s cock.

And then she starts moving her hand, and you feel the most intense pleasure of your entire life. You melt into putty in your sister’s hand, and your moans grow louder. Cat leans down and kisses you deeply. It’s a deep and passionate kiss, and her hand is moving swiftly but firmly against your lengths. Touching your own clit pales in comparison to the feeling of Her fucking herself against your clit. You whimper into her mouth, and your hands grab her hips. 

She breaks the kiss again, and her lips to your collar bone, beginning to leave more hickies. Your whimpering moans become louder. It’s so much stimuli, all amazing on their own, the total pleasure greater than the sum of its parts. Your grip on her hip tightens, and you hear her moan louder in response.

“Fuck, baby! You feel so good,” your sister moans out between nibbles on your shoulder.

“Nngg, Cat. Cat please, please Cat,” begging whines escape your lips.

Your sister lifts up from you, she’s looking deep into your eyes. “C’mon baby bird, tell your big sister what you need. Speak.”

“Cat please make me cum! Please! Fuck, I need it Cat, I need it so bad pleaaase!” You cry out in desperation, quivering at the command.

“That’s my good baby sister, of course I’ll make you cum.” Your whines intensify, “Fuck baby, I’m so close too. Let’s cum together, okay Birdie? That’s it babygirl, cum for me, cum for your big sister. Fffuuck!” Cat’s voice hitches, and you feel her cock start pulsing against your clit.

Then it happens, you feel yourself pulsing and something in your mind shatters. Wave after wave of absolute bliss wash all across your body, starting in your clit as it pulses. You feel a warm watery splash across your belly, and your muscles all spasm in pleasure. Your moans are practically screams of pleasure, and your sister’s moans reach a crechendo. 

“FFffuck, Birdie fuck fuck fuck fuck, fuck yes god fuck!” Catherine cries out, and you feel a small dribble leak out of her cock onto your pelvis.

“Thank you thank you thank you,” you pant out, and you pull your sister down to your level and meet her with a kiss. She falls to your side, and you lose yourself in her lips, in the waves of aftershocks, in the perfect golden hour on the rooftop of your school, and most importantly in your sister’s embrace.

At some point you stopped kissing, and curled up in her arms, face buried somewhere between her shoulder and her chest. She shooshes you, cooing sweet nothings to you, and the rest of the world melts away. 

You wake up, still in your sister’s arms. The sun set, the sky still lit by the last embers of twilight. Cat is looking down at you with those beautiful brown eyes of hers, full of love. She’s gently stroking your hair. You nuzzle deeper into her, and she softly chuckles.

“Hey sleepy head, you have a nice nap?” Your sister gently coos in your ear.

“Nnng, how long was I asleep?” You sleepily ask. 

“About half an hour. Seems like you needed it though baby bird.” She pulls you into a soft kiss. Shorter than the previous ones, but so so tender. 

You pull away, and look up at her with eyes full of fear and hope and vulnerability and trust. “Um, um, Cat?”

“Yes baby bird?” She replies.

“What um, what does this, y’know, uh, what are we?” You timidly ask. You trust her with everything.

“We’re sisters, dummy. But, I want you to come visit me at campus sometime. I want you to meet my friends, as my girlfriend. If you want.” She hands you your shirt.

You take it, and put it back on. You reach for your hoodie too and put your arms through the sleeves. She gets dressed again too. You both stand up.

“I want that, I want you, I love you Cat,” You hug your sister. Tears of joy blurring your vision.

“I love you too, Birdie,” Your girlfriend hugs you back, and then pulls you in for another kiss.