Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/ works/3879388. Rating: Explicit Archive Warning: Underage Category: F/M Fandom: Supernatural Relationship: Dean_Winchester/Sam_Winchester Character: Dean_Winchester, Sam_Winchester Additional Tags: girl!Dean, posessive!sam, Incest Stats: Published: 2015-05-05 Words: 1735 ****** A Sister's Love ****** by fallingoverfeelz Summary It starts when Sammy is about 13. And yes she knows it’s wrong. Ok? You don’t have to fucking tell her that. It starts when Sammy is about 13.   And yes she knows it’s wrong. Ok? You don’t have to fucking tell her that.   It’s wrong that she fuckin- that she… wants Sammy like she does. She knows that. But jus cuz you know something doesn’t make the thought go away. She thinks about Sam like that. Like a big sister shouldn’t. About him touching her, kissing her, owning her.   But, anyway, it starts when Sammy is about 13.   ***   He’s complaining that he’s never kissed a girl before and that those asshole jocks at school are making fun of him for it. She tells him to tell them to fuck off but he says that that won’t solve the problem. It’s been happening for a while. He tells her that he actually wants to, but he’s scared. Plus, he says he doesn’t want to mess it up.   So, naturally, she offers herself up for practice. And she tries to tell herself that it’s not because of that, it’s because she wants her brother to get some action and be prepared for it. But she knows.   He grimaces at her and tell her to shut up before he goes off to do his homework.   ***   A few days later she’s listening to music in their room when he comes in and turns the music off. He looks her in the eye and says “Does that offer still stand?”   She nods her head and leads him to sit next to her.   She’s already damp by the first press of their lips. And she can tell he’s nervous, but she tells him to not freak out before she starts moving her lips. Eventually he gets the pictures and starts kissing back. And the first time, that’s all it is. Just their lips, no tongue or heated breaths. Just that. Sammy utters a breathy “Thanks, Dean.” Before he leaves the room, and she locks herself in the bathroom until she comes.   ***   They practice a lot more after that. Sammy is a quick study and after a few days his tongue is pushing back into her mouth and he’s sucking on her lips. He’s aggressive about it and it makes her shiver. She has her arms around his neck while the kiss, she had told Sam to put his on her hips but really she wanted them everywhere. All over her.   It becomes regular, them kissing. If Dad was off on a hunt she would greet Sammy home with one. Sometimes when they’re watching T.V. Sam would just scoot over and kiss her and they’d make out while the episode played out.   He gets handsy after a week or two. His fingers running up and down her side, her back, and she can tell that he’s unsure of what he’s allowed to touch. He presses himself into her breasts more, pulling her close and kissing her harder. She can always feel his erection and it makes her breathe heavy. One day she’s in his lap on the bed, and because he’s still kinda short she has to lean down, but Sam likes this position a lot.   He’s sucking on her tongue and she’s whimpering for it when he pulls back and asks “Can I touch you?”   She wants to say yes to everything, but she formulates a response in her mind before answering. “Yeah Sammy,  you can touch me anywhere you want. I’m yours.” And she hopes that’ll get the message across.   He looks at her for moment, eyes shining up at her, lips shiny with spit. “All of you?”   She smiles. “Yeah Sammy. All of me.”   So they go back to making out and now that he’s got what he needs his hands are all over her, her back, her stomach, rubbing over her breasts until he says “Take off your bra, Dean.” And she does, because yeah, he got the message.   That night while Dad is gone Sam wraps his mouth around Dean’s nipples and suckles so softly she keens into it. He messages her breasts and kisses her everywhere, sucking on her lips and tongue and neck. He kisses down her stomach until he gets to her panties and then he doesn’t even asks, he just takes them off while Dean complies and then she’s laying there, under her 13 year old brother’s scrutiny and his eyes are fixed on her cunt, where she’s wet and needy. He looks up at her.   “Show me how to finger you.”   ***   Another week later and Sam is licking into her pussy and she’s riding waves of pleasure. Her hands are fisted in his hair as he gulps her down, one hand on her breasts and the other teasing her clit. He told her the first time he ate her out that “ That was amazing. I like the way it smells, Dean. I like the way it tastes too. We’re doing that from now on.”   And she couldn’t tell him no, not that she even wanted to. Sammy’s always been stubborn, always got what he wants and she knows it’s terrible but she wants him to take her, whenever he wants, however he wants. She’d never deny him anyway.   After he fingers her and she’s shaking with her orgasm he tells her, lips glistening, “You’re gonna suck me off, right?”   And of course, she does. His cock is bigger than she expected, but she knows it’ll grow, just like the rest of him will. She slips it into her mouth and sucks it as best she can, and he comes in minutes and commands her to swallow it.   So she does, and looks up at him with a smile on her face afterwards.   ***   Dad is gone on Sammy’s 14th birthday, and Sam isn’t even angry because he’s getting what he wants that night. He had woken up beside her- they had taken to sleeping in the same, tiny bed, and said “For my birthday, I wanna fuck you.” And then had slipped his fingers into her and gave her three orgasms in quick succession.   She couldn’t say no after that.   So she splurges buys him a cake because she can cook some stuff but can’t bake for shit, and she gets two candles because that’s all she’s got money for, “Each one stands for 7 years Sammy”, and he grins like a dog while they eat it. Well, he wolfs his down and stares as Dean finishes hers before he’s pulling her into his arms, kissing her hard and undoing her bra as they stumble to their bedroom. He’s gotten a little taller but he’s still maybe a little above her shoulder, where he plants kisses and sucks hard.   They get on the bed and Sammy’s mouth is running while he takes off her clothes and sucks her nipples and plays with her clit. “God Dee, you’re so beautiful, most beautiful girl I’ve ever seen. I wanna fuck you so hard, so bad, can’t wait to come inside you, don’t even care that you’re my sister, God I love you so much.”   And they lock eyes when he slides inside- she had gotten birth control so he didn’t have to use a rubber for his first time, and she can see the love he has for her right there, blazing behind his pupils. As he’s thrusting in and out of her, their breaths heavy as she rubs on clit- she wants him to focus on how good it feels- the glide slicked by her own wetness and he’s going hard as he promised, kissing her so softly that it makes her eyes roll back and she almost misses it when he says:   “You’re mine, Dean. All mine.”   And she whimpers because that’s all she’s ever really wanted, to belong to Sam. To know she’ll have him forever. Her beautiful, fantastic brother. “Yours, Sammy.”   “My sister, my girlfriend,” And then he’s thrusting harder and they’re getting erratic and in moments he stills and she feels him pulsing inside of her while she gets off on the feeling, coming after him and bending into the sensation as she cries out.   They make out afterwards, soft and slow, whispering words of love to each other while they giggle and bask in the after glow. Sam kisses her neck and her lips and tells her that he’s in love with her.   She smiles softly and says the same.   ***   Sam is almost 18 now. And they’ve settled into their relationship- around their father, of course.   He fully knows that Dean belongs to him, and he acts the posessive bastard Dean has always known him to be. He doesn’t even ask her before he takes off her shirt and bra and bends down- yeah, because he’s a fucking giant now- and takes a nipple into his mouth. When Dad’s gone on hunts far away and he leaves Sam behind to watch over Dean, because Sam’s lanky awkwardness has evolved into this lithe, tall frame with muscle underneath that gorgeous tanned skin- Sam doesn’t let her wear clothes. He likes to know that she belongs to him. When she cooks dinner he comes up behind her and touches her wherever he wishes, and she doesn’t complain.   When they sit on the couch together he casually slides in a few fingers and pumps away until she’s moaning and he lays her on her back, takes out his now very impressive cock and slides it inside her. He fucks her however he wants, sometimes fast, sometimes slow and hard and groundbreaking. But he always makes her come first.   And they still kiss. Now, better than ever. Their tongues dance together and she leans her body into his and he holds her waist, those large palms spanning over her ass when he lowers his hands. That’s when she feels safest- in his arms. That’s when she feels the most loved she ever has. And from the way she can see Sam looking at her, he’s just as gone for her.   The day before Sam turns 18, they’re lying in bed together after sex and Sam tells her that he’s going to marry her one day, and that they’re going to have a nice house and a big family and that he’s going to get them out of this.   She believes him. Because she knows he’ll make that happen. And even if it doesn’t, She’ll follow him to the ends of the earth. Please drop_by_the_archive_and_comment to let the author know if you enjoyed their work!