Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/2345162.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Supernatural
  Relationship:
      girl!Dean/Sam_-_Relationship
  Character:
      Sam_Winchester, Dean_Winchester
  Additional Tags:
      Gender_or_Sex_Swap, Always_Female_Dean, Underage_Sex, Cunnilingus,
      Barebacking, Impregnation_Kink, First_Time, Sibling_Incest
  Stats:
      Published: 2014-09-22 Words: 2693
****** Fill Me Up ******
by customuserhead
Summary
     Kink Meme Prompt: I'd really love a fic where Sam fucks girl!Dean
     bare and Dean is begging for Sam to fill her up with his come, knock
     her up, etc. Pushy!bottom!Dean preferred. I also prefer girl!Dean
     with short hair, but that's just me. No actually impregnation,
     please--I'd prefer that Dean is on the pill and they both just get
     off on the fantasy of getting her knocked up. Sam no younger than 14
     for this one, please. No scat or non-con. Bonus points for Sam
     enthusiastically eating Dean out.
A cloud of steam surrounded Sam as he emerged from the bathroom. Deanne was
sitting on the couch with her feet propped up on the coffee table. She looked
up from the TV where Captain Kirk battled tribbles. She’d seen it a dozen times
so she wouldn’t miss anything. That’s not how she felt about her little brother
lately. It seemed like he’d shot up six inches when she glanced away. The
little boy who used to run around in his tighty-whities playing He-Man was
never dressed in anything less than jeans and a t-shirt these days. His new
found privacy made her uncomfortable. He used to tell her everything, and now
he was a closed book.
He crossed to the bureau and stuffed his dirty clothes into the laundry bag
lying on top. He wasn’t a little boy anymore. His shoulders were beginning to
widen, and sparring had become an increasing challenge. He might not have the
bulky muscle of the men she sometimes hooked up with, but he was strong and
knew how to use that strength.
Sam wasn’t a stallion, not yet. He was more of yearling – lean and fast and
just beginning to stretch out and feel his oats.
She watched him dig around in his duffle bag for a flannel shirt. His shoulders
were hunched and his hair fell over his eyes. It was fractionally longer than
hers at this point. She needed to tell him to get it trimmed before Dad got
back, but not right now. She’d wait till the day before Dad was due back. Sam
would have to get it done right away and wouldn’t brood over it for days. She
hated being the enforcer, hated even more how it put a chill between them.
“Hey, Sammy, tribbles!” she said.
“It’s Sam,” he mumbled. “And we’ve watched that a dozen times.”
Deanne sighed. She wiggled her toes and pretended to watch the TV, but she was
watching him from the corner of her eye as he bent to pick up a book from the
pile he’d left beside the bed. She swallowed the lump in her throat. He
seriously needed new jeans. Like, how were the girls not grabbing that in the
hallways at school?
“Sam, dude,” she said. “Come here and sit down.”
He stood and turned with a frown. “Why?”
She waved the remote at him. “Whatever you want.”
“Right.”
“Seriously.”
“Yeah?”
She crossed her heart with her little finger. “Pinkie swear.”
A small smile tugged at his candy-colored lips. “Okay.” He plopped down on the
couch and propped his feet up on the coffee table beside her. She handed him
the remote, and he began flipping through channels. He settled on a documentary
about wolves, and she half paid attention. Sam rested the remote on his thigh
with his fingers wrapped loosely around it. His knuckles were scraped up for a
salt and burn they’d done just before John had gone off on some mystery hunt.
Sam was like a puppy who hadn’t grown into his feet. His hands were long and
strong, but they turned the pages of books and dressed wounds with such
gentleness. Seeing that hand wrapped around the remote made her mind go to bad
places.
It’s not like she was blind. His jeans weren’t just tight in seat. She really
needed to get the boy some new jeans before they caused him some damage or he
got jumped by the girls at school. In her mind, she saw those long scraped
fingers wrapped around flesh, his flesh, hard and leaking …
“Sam, you like girls, right?” She wanted to slap herself the minute the words
left her mouth.
“What? Yeah, why would you ask that?” He’d half-turned toward her with a look
of shock.
She shrugged as nonchalantly as possible and acted like she was still watching
wolves. “You never talk about ‘em.”
His voice was almost a squeak. “Just because I don’t talk about everyone I like
the way you do, doesn’t mean…”
She turned toward him with her arm on the back of the sofa. “No, no, hey, I
didn’t mean it like that. It would be cool if you did like guys, you know, but
that’s not what I meant.”
He picked at a frayed thread on his jeans, and his stupid bangs fell over his
eyes.
“So, is there someone?” she asked.
He shook his head. “No, not really.”
“See, I don’t get that,” she said.
He looked up with a huff. “Really?”
“Yeah, you’re really cute.”
He rolled his eyes. “Puppies are cute.”
“Girls love puppies,” she said with a grin. “Anyway, you’re not a little boy
anymore, Sammy … Sam.” She pinched his bicep. “Getting’ muscles and
everything.”
A blush rose in his cheeks. “Shut up.”
“I know girls.”
“Yeah, you do.”
“I don’t mean it like that. I mean I know girls who like boys, and I am a girl,
and I know what I like, and …”
“Yeah, yeah,” he said as though she was blowing smoke up his ass. “Jennifer
Douglas back in Springfield liked me,” he confessed.
“Yeah? She was cute,” Deanne said. Despite that piggy little nose, she thought.
“So, did you kiss her.” She slid her hand along the back of the couch and
brushed the hair from his eyes.
“No,” Sam said. He shrugged. “I mean, I might have but we moved, and …”
“Yeah,” Deanne said. “Have you? Kissed a girl, I mean?”
“No.” He bit his lip, and she imagined it might taste like bubble gum or cotton
candy.
Deanne’s pulse quickened. She shouldn’t say it, but she knew she would. “I
could give you some pointers.”
Sam looked wide-eyed at her. “What?”
“Just, you know, like training,” she said. “So when the time comes, you’ll be
ready.”
“Training? Like shooting or picking locks.”
“Yep,” she said. “Just like that.” She leaned forward as though his mouth was a
magnet and brushed her lips across his.
Sam gasped. “Dee.”
“It’s okay, Sammy.”
“No, you don’t know what you’re doing,” he said. It sounded as though his voice
was on the verge of breaking.
“Sure, I do,” she said. She caressed the back of his neck with her fingertips.
“I’ve kissed lots of people.”
“I know,” he said and surged forward. His mouth met hers with enough force to
bruise her lips. She would have decked any other guy for unnecessary roughness,
but this Sammy and his enthusiasm was so unexpected she let his momentum carry
her to her back with him on top. The kiss was messy and deep and fucking hot.
His mouth didn’t taste like cotton candy. It was infinitely better, and he was,
as always, a fast study. He kissed like he was starving for it.
He sucked on her tongue, tugging just a little and letting go before delving
back into hers. Despite his fervor, he wasn’t too fast, but he was damned
thorough, twisting over Deanne’s tongue, dipping into her cheeks and teasing
the roof of her mouth.
Deanne’s fingers were twisted in Sam’s hair. Her thighs cradled him, and she
wrapped her calves around his. She could feel his hard on pressed against her
crotch, and she was sure she was soaking her panties.
“Sammy,” she mumbled against his lips. “Doing so good.”
He dropped his forehead against her shoulder. “Shouldn’t.”
“It’s okay,” she panted. She rolled her hips, seeking friction against his
cock. He groaned and trembled. “It’s okay.”
He pushed off her and flopped onto his ass at the opposite end of the sofa. His
face was flushed, and his lips were wet with spit, red and delicious. A wet
spot grew on the crotch of his jeans. Jesus, he’d creamed himself.
“Hey.” She sat up. “It’s just training, right? Better this happen with me than
a date.”
Sam shook his head, but he was just freaking out a little. He needed not to
panic. She grabbed the hem of her t-shirt and pulled it off over her head.
“Oh God,” Sam breathed.
She reached behind her and unhooked her bra. She eased onto the center cushion
and dropped the bra to the floor. Her breasts weren’t particularly big, but
they were firm and high – tipped in pale pink.
“You want to touch?” she asked. “You can.”
Sam’s Adam’s apple bobbed when she took his wrists and lifted his hands. They
were so warm on her skin, but he just sat there frozen for a moment. Then, he
blinked as though waking, and those big, gentle hands that she’d taught to tie
shoes when they were little and chubby caressed her skin. His fingertips traced
the curve of her breasts, and his thumbs brushed across her nipples sending
sparks to her pussy.
“Yeah, just like that,” she whispered.
Sam kneaded the small globes. His mouth hung half open, and his eyes were
locked on her breasts. She got up on her knees and twisted her right nipple
toward his soft, cherry lips. She ran her hand over his hair and urged him
forward. Sam latched on like a starving babe. His arms went around her waist,
holding her close. He suckled her nipple to a hard nub and moved to the other.
Blood pulsed in her pussy.
“Oh God, Sammy,” she moaned. “Good, good job.” She heard the time-worn
expression fall from her lips, and somewhere in the back of her head
acknowledged how fucked up this was. She also knew she wasn’t going to stop.
Sam’s hand slipped downward and grasped her ass cheek. “Yeah,” she said. “Doing
great.” The encouragement was second nature to her.
His mouth never left her breast as his hands went to the fly of her jeans and
unbuttoned them. She looked down at the spit glazed skin where his lips were
sealed around her pebbled flesh. His deft fingers worked her zipper down, and
he thrust his hand into her panties. The moment his fingers touched her clit,
she humped helplessly against them.
Sam’s mouth came off her nipple with a wet pop. “Dee,” he whined. She hugged
his face between her breasts and kept humping, but it wasn’t enough. She let
go, toppled herself backward onto the couch, and began wriggling out of her
jeans and panties.
Sam looked wrecked. “We can’t,” he said.
“It’s okay, Sammy,” she said. “Come on. Let’s get you out of those wet things.”
She kicked her jeans to the floor and grabbed the waistband of his.
“No, Dee,” he said. He grabbed her wrists. “What if …”
“I take my pill religiously, Sam. And this is training, right?” It was
bullshit. She knew it. She knew he knew it.
He licked his lips. The crotch of his jeans bulged, and she had to see that
secret. His fingers were wet with her juices. She twisted out of his grasp and
took his hand in hers. She sucked his sticky fingers into her mouth, licking
between the webbing, and sucking obscenely on the tips as she pulled them from
her mouth.
“It’s up to you, bro,” she said.
He nodded and began to work his fly open. She pulled him into a kiss as he
shoved his jeans and shorts around his thighs. He followed her down into the
cradle of her thighs. She reached between them and guided his cock to her
pussy. She tipped her hips up and rubbed the head against her clit, parting the
labia, and urging it into her. Sam slid right in, the fucking over-enthusiastic
fourteen-year-old.
“Fuck!” she exclaimed. Her little brother might not have the biggest cock she’d
ever taken but it was up there in the top three. It filled her perfectly,
stretching her wide, and rubbing up against her g-spot.
Sam froze. “Are you okay?”
“Yes! Fuck yes, fuck me,” she said.
His lithe body undulated, and she dug her heels into his ass cheeks and rolled
her hips to meet his thrusts.
“Sam, Sam, fuck.” She was completely unprepared for how not training this was.
Sammy had always filled the place in chest where her heart lived, and now, fuck
now he was everything. She was fucked.
“Dee,” he gasped as he mouthed wet kisses along her neck and jaw. “You feel so
good. You’re sure about the pill.”
“Yeah, yeah,” she whispered. She’d only had sex bareback once – the first
drunken time. She remembered it as a disappointing dream that left her stinging
for two days. Every other time had been latex compromised. Now, her little
brother was going to come in her, and it was the dirtiest, wrongest, hottest
thing she could imagine. “Want you to come in me, Sammy.”
He groaned. It was a good thing he’d already creamed his shorts once or he’d
have already blown his load. “Want that too. Wanna …”
The couch springs creaked in protest as Sam burrowed deep and hard into her.
“What, baby?”
He shook his head against her shoulder.
“What do you want, Sammy?” Her voice was breathy with arousal and exertion.
“Wish I could knock you up. Wish it could be me someday.” His words were
pressed to her skin like kisses that set her afire.
“Yeah, yeah, I wish that too.” Her nails sank into this back. “Love your big
hard dick. Fill me up with come, Sammy. Wanna have your baby in me.”
Sam pulled her ass up off the couch and pushed deeper. She could feel him
bottom out.
“Yeah, get in there deep,” she said. “Fill me up.”
He pushed up on his right hand with his face just inches above hers.
“You’re mine,” he said. “Hate it when you’re with other boys. Wanna knock you
up and show everyone.”
“Yeah, me too,” she gasped.
“They’ll see your belly, know you’re mine.”
She could picture it, almost feel it, her belly big and heavy with Sam’s baby.
Everyone, even Dad, would know that she was slut for her little brother. That
he loved her. Only her. They belonged to each other. Sam would never leave her.
“Only mine,” he whispered.
She arched off the couch with a cry. Her pussy clutched at his cock, and she
trembled with pleasure. Her hips fucked furiously, driving her little brother’s
cock into her as she moaned and shook. Suddenly, Sam stilled, eyes squeezed
tight, and hands gripping her hips to hold her still.
“Stop, stop, stop,” he pleaded.
She felt his cock twitch inside her. It was happening. Sammy was coming in her,
filling her with his seed, and she could imagine the natural outcome – her
belly big and round with her little brother’s baby. Her pussy clenched, and Sam
grimaced at the over-stimulation.
“I’m all full of you, Sammy,” she whispered.
“Yeah, yeah,” he said. He let his cock slip free and scooted backward. Bending
down, he buried his face between her legs and devoured her. Her hips jerked at
the renewed stimulation. She’d been eaten out a few times, but never with such
abandon, never with the guy’s come leaking out of her. Sam flicked at her clit
and licked deep as though she was filled with hot fudge and strawberries.
Within moments, she was riding his face and practically crushing his head with
her thighs as she shook and moaned through another orgasm. She petted his hair
as she came down from the high.
Sam looked up at her. His face was glazed with their juices. “Was that okay?”
She smiled. “A-plus, Sammy.” She tugged at his hair. “Come here.”
He crawled up over her, and she kissed his bitter, salty, sticky lips.
He looked overwhelmed. He laid his palm on her flat abdomen. “What if?”
“Your seed is hooking up with my egg in there?”
“Yeah,” he agreed. His throat worked a lump down, and he bit his lip. “It’s so
fucked up.”
She smirked. “Welcome to our life.”
He looked away shame faced and maybe a little disappointed.
“It’s okay,” she said. “It can’t happen.” She pulled his face down and kissed
him. “But if you keep fucking me like that, I’ll never want anyone else.”
Sam looked at her questioningly. "Yeah?"
"Hell, yeah." She grinned.
                                   The end.
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