your big sister Lena moved in with you today. you picked her up at home in a U-Haul you'd rented for the day; dad helped you pack all of her things into the truck, while mom harassed her oldest daughter about being responsible and getting a job quickly. you watched between trips, arms full of boxes, as your big sister shrank bit by bit into herself.
“don't worry, mama, you know i'll be keeping an eye on her!” you said. mom smiled, but you cringed when your sister shrank just a little bit bit more. you'd have to make it up to her. maybe on the way out you could stop at that ice cream place you both loved as kids.
the first thing she said when she got in the truck was a pitifully murmured “i'm sorry…”
you bravely resisted the urge to whip your head around and slam on the brakes, instead choosing to take a deep breath and ask her “why?”
“you… you need me to get a job so that we can live together. and most days i can't even get out of bed, so i'm just gonna be a-”
“mom and dad didn't tell me that. you can't get out of bed?”
“no, i just- college was hard. i'm just still tired after graduation. i'll be better soon, it's okay. don't worry about me.”
“you spent our entire childhoods worrying over me, it's my turn!”
mercifully, she chuckled, and a ball of tension in your chest you didn't know was there loosened by a fraction. “can we stop at-”
“Polly's? come on, you haven't even been looking at where we're going, have you?” you teased.
she went red, finally looking up from her lap as you pulled into the parking lot of Polly's, the local ice cream place. “oh.”
you smiled over at her. it took a second, but she met your eyes, noticed your smile, and gave a small smile back.
two ice cream cones, several pit stops, and four hours later, you pulled up to your house. you share rent for the place along with three other girls, all of whom you've kissed at one point or another, with varying levels of seriousness. they all approved of your sister moving in, helping you clear out the fifth bedroom that you'd all been using as storage so she'd have her own room. they'd even pitched in to buy her a bed (albeit a cheap one off of Amazon, but still).
you sent the house group chat a message before you let your sister get out of the U-Haul. by the time she got out and started moving towards the back of the truck with a resigned slump, a butch and a very fit femme had hustled past her, said “hi, nice to meet you, we've heard so much about you, let us get your things for you” and handed her off to the last member of your household, Sarah.
Sarah smiled sweetly at you, gave you a peck on the cheek, and took your sister by the arm. “hey! Lena, right? Penny talks about you all the time. nice to meet you, i'm Sarah. we made plenty of dinner earlier, you want some?”
Sarah threw you a smile over her shoulder. you smiled back.
a few hours later, thanks to the efforts of two butch lesbians and two fit femmes, Lena is moved in and unpacked and your housemates have vanished back into the metaphorical woodwork, leaving you to spend time with your sister alone.
“your bed is so comfy,” she says. “wish i could sleep here…”
your blush covers your entire face, and you go a little light headed. no, keep a lid on it. you're fine. she doesn't mean it like that.
“i've been saving up money. in a couple months, i can get you one just like it, if you want.”
“no! you don't- it's fine. my bed will be fine. don't worry about it, Penny, it's fine, i'll have a job soon and then i'll- i'll be able to buy my own bed.”
your blush cools off, replaced instead with anger at your mom and dad. you slide a little closer to her, “you let me take care of you, Lena, or i swear to god-"
“fine, god you freak!” she half-shouts, scooting away from you by a couple inches. not too far, though. “what kind of idiot sister wants to take care of an invalid like me any-”
you lunge at her, and she lets it happen. falls back on the bed as you push her down by the shoulders and straddle her, pinning her arms to her side as you shout “take it back! say something nice about yourself!”
she grins, comfortable in the familiar motions even with unfamiliar words. you've never actually beat her in a fair fight, but whenever you jump on her like this she always goes down easy.
you grin, and your hands leave her shoulders. it takes her a second to realize what you're about to do, but by the time she goes to mount a defense it's far too late. your hands are already dancing up and down her sides, only half-blocked by her arms and your legs. she guffaws and bucks, trying to get you off of her. but this is the only way you've ever won a fight with her; underhanded tricks.
“oh- hahaha! - okay, i give up! i- wheeze - i'm smart!!”
you relent, panting for breath yourself and unconsciously leaning forward. for a second you don't realize what kind of position you're in. the top of your head is buried in the pillow next to your big sister's head, your mouth right next to her ear, your bodies pressed against each other.
it slips out of you involuntarily, said a million times to Sarah in situations far too like this, but now rushed out in one breath into your sister's ear: “good girl.”
Lena shivers, whispers “whu…?”
and suddenly you've come back to yourself. the position that you're in is clear, and you scramble off your sister. she stares at you with wide eyes, your own like saucers staring back. your faces are both flushed, and you're panting. your big sister turns her face away, and you thank god that she's not looking when you reach down to adjust your hardon.
your hand comes out of your pants begrudgingly, feeling hypersensitive and needing to do something about it. maybe once you're done hanging out with Lena you can go fuck Sarah into her mattress. maybe she'll let you call her ‘big sister’ again.
Lena looks back over at you, and your blush gets deeper.
“sorry,” you say, “i just… Sarah does that a lot, and when she-" you swallow your tongue, aware that you're digging the hole deeper with every breath.
Lena turns to you with interest. “so you and Sarah, huh? mom and dad definitely don't know about her, or i'd have heard about this way earlier. are you two dating, or what??”
“Lena!” you protest, “i'm not telling you that! that's private stuff, not-”
“no no, i know what you're about to say, but it's absolutely for sisters to talk about!”
you almost protest, almost tell her that the logic she used for everything when you were kids wouldn't work anymore, but… this is the happiest and most excited you've seen your big sister all day. so you open your stupid mouth, and you tell her the story of how you and Sarah started your relationship.
something about being alone with your big sister again for the first time in almost five years loosens the tight hold you keep on your heart and your tongue, and you tell her a nearly unredacted version of the story, sex scenes and all (though, admittedly, more of the ‘fade to black’ variety).
it's a long and embarrassing story, and Lena asks you for details, and you can't stop the words from tumbling out. you tell her how you and Sarah helped heal each other in a very real way. you shyly admit that's where your new confidence comes from. you blush when your sister tells you she thinks it's kind of hot.
“in a sisterly way, obviously.”
at some point during the story, maybe when you're crying through the story about Sarah saving you from being assaulted, the distance between you vanishes, and everything feels right again. your sister holds you close, your legs tangled together while you fit neatly into her shoulder.
you finish the story, and your sister murmurs “oh babygirl…”
frustrated tears fill your eyes, though you're sure Lena takes them to be tears about the story you just finished telling. the problem is that you're so close to her right now. that your lips are hovering over her neck, that you're keenly aware of your cock tightly pressed between your bodies, that it's taking everything you have to not start grinding on your big sister's leg right now.
your hips buck, just a fraction of a twitch, and Lena becomes a flurry of limbs and movement that you can't parse for a second. then, a second later, you're on your back and your big sister is above you, her arms pillars to either side trapping your head in place. her brows are in a deep furrow, but her eyes are wide open and staring into yours. you stare back, unafraid. your sister would never hurt you.
“i'm sorry,” she says, then gives you everything you've ever wanted.
she all but collapses on top of you, no longer pillars but arms wrapping around you, fingers winding into your hair and tugging. you groan and your mouth opens; your big sister takes advantage of it and captures your lips with her own, her tongue snaking into your mouth. the rest of Lena's body relaxes and presses you into the mattress. you can't do anything but sit stock still, sure that this can't be real.
“i'm sorry, Penny, please… please i need you so bad, i can't- i can't help it anymore, please fuck me. please, Penny, i'm sorry, i need you to fuck me, i'm sorry,” she rambles. you groan incoherently, unsure if this is a dream or a nightmare.
before you can come to and say anything, Lena has already shifted and gotten your pants down far enough for your cock to spring free. she rubs on it for a moment, and you start whining.
“i know, i'm sorry! i'm sorry, please i just- fuck, please just let me- Penny please please please!”
you think you nod. probably frantically. Lena thinks you're scared, but you're really just desperate. you've been dreaming of this for years, and only hesitantly played it out a couple times with Sarah. you're trembling not out of fear, but out of excitement.
you stutter as Lena lifts herself up and starts to align her cunt with your cock. “please… want… you…” you manage to push out.
“no babygirl no no no, please don't say it! you keep talking about Sarah, please, please just- please i want you to be mine, Penny! please don't make me go!”
“yours… your- your sister, yours,” you groan. she lines up, resting your tip at her entrance.
tears fill your sister's eyes. “do you… do you mean it?” she asks.
then, before you can answer, she slams down onto you, taking your entire length down to the base in one smooth move. tears fill your eyes too, and you lean up to kiss your sister.
one more time, she lets you turn the tables and falls backwards as you tackle her. you land on top of her, pinning her down. “i love you,” you huff, pulling out halfway before snapping your hips to slam back into your sister. “i love you, sis.”
“i love you too, little sis…” she cries.
you lose track of how many times you cum inside your big sister that night. you fall asleep tangled together, half-hard and still inside her, your bodies and bed covered in slick cum. that's a problem for tomorrow.