Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/7970887.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      F/M
  Fandom:
      Supernatural
  Relationship:
      Dean_Winchester/Sam_Winchester, John_Winchester/Mary_Winchester
  Character:
      Dean_Winchester, Sam_Winchester, John_Winchester, Mary_Winchester
  Additional Tags:
      Extremely_Underage, always_a_girl!Dean, Alternate_Universe, Brother/
      Sister_Incest, Toddlercon, Voyeurism, Masturbation, Blow_Jobs, Vaginal
      Sex, Loss_of_Virginity
  Collections:
      Anonymous
  Stats:
      Published: 2016-09-06 Words: 1745
****** Practically Grown Ups ******
by Anonymous
Summary
     When six-year-old Deanna catches her parents having sex, she gets
     curious. Luckily, she has a two-year-old brother willing to play with
     her.
Notes
     I in no way condone the behaviour shown in this fic. Do not re-enact
     what you read here.
     Dee is 6. Sam is 2.
     Written for this prompt:
     Sammy is 1 or 2, still in a crib, can talk a little bit (enough that
     Sam can express liking something) and Dean (5 or 6) is having sex
     with Sam in a crib. Sam can be a girl or a boy. Dean can be a girl or
     a boy. They can both be boys. As long as one of them is a boy and
     they both fully enjoy the penetrative sex I don't care. I don't care
     who tops or bottoms. It must happen in a crib. No scat, snuff, blood,
     violence, non con.
                             Practically Grown Ups
Ever since Dee had walked in on her parents having sex, she couldn't stop
thinking about it. She had woken up over a nightmare and went to her parents'
bedroom. They always left the door cracked open so they could hear her and
Sammy in case either of them needed something. When she heard weird noises
coming from within, she had peeked inside to see her mommy bouncing on top of
her daddy, his big, thick thingy going in and out of a hole in her privates.
They both kept making weird noises, almost like they were in pain. They didn't
even notice when she walked in.
"Mommy? Daddy?" They had leapt apart, yanking up the blankets to cover
themselves. "What are you doing?"
They had quickly dressed and explained that they were having sex, something
that grown ups did sometimes, but it was only for grown ups and that it was
supposed to be private. Dee had heard the word before from an older kid at
school who said that was where babies came from. Her parents agreed. "You're
gonna make another baby? Is me and Sammy not good enough?"
"Oh, no, Deanna, no. Sometimes grown ups do it for . . . um, fun."
Fun. It was supposed to be fun.
Once they sent her off to bed, she had felt her private parts a little bit. It
was nice, actually. Putting two fingers inside a hole she hadn't ever noticed
before was even nicer; kinda tingly, but in a good way. Two nights later, she
had heard funny noises coming down the hall awhile after they had tucked her
into bed. She had snuck to their room and watched through the partly-open door.
Her mommy had put her daddy's thingy in her mouth, then crawled on top of him
and rode him. Dee left before they finished because down there had tickled and
she wanted to touch it again.
Now, though, it had been a whole week since she had caught them, and she still
couldn't stop thinking about it. Why did grown ups always have all the fun?
They got to watch scary movies and drive and drink beer. If only they knew what
it was like to be a kid, they would understand how hard it was. Besides, Dee
was practically a grown up anyway. She was the oldest of her friends at school,
and her teacher was always telling her she was mature. Daddy had even let her
use a knife the other day, and adults didn't let little kids use knives.
She had watched her parents change Sammy's diaper enough times to know that he
had a thingy just like dad. True, he was still only two, but she had heard
Mommy and Daddy talking about potty training him soon so he was getting up
there, just like her. Anyway, she was the bigger sister, and if she said
something was okay, then it was.
Mind made up, she hopped out of bed, only wearing a knee-length nightdress,
white and silky like her mom's. She tiptoed down the hall and checked her
parents through the door; they were sleeping. She then tiptoed just as quietly,
if not quieter, to Sammy's room.
He was asleep in his crib. He almost always slept through the whole night
nowadays.
She climbed into his crib, like she had done a bunch of times before to play
games with him. She shook him gently. "Sammy. Sammy, wake up."
His eyes fluttered open, and then he rubbed them with his fists. "Bottle?"
"No, no bottle right now," she whispered, checking the door she had closed
behind her. She smiled back at him. "Did you want to play a game with me?"
He nodded sleepily. "Kay kay."
"But it has to be a secret, like when I pooped my panties that one time."
He nodded again. "Kay kay."
She furrowed her brows, and reached for his diaper. "So we're not gonna tell
Mommy or Daddy, right?" Sammy just nodded a third time, and she took off his
diaper. It was wet and smelled like pee, anyway. She threw it out of the crib.
Sometimes Sam took his diapers off in the middle of the night. Her parents
wouldn't think it was weird to find it on the floor.
He stood in front of her, his small thingy right in front of her mouth. Just
like Mommy had, she put it in her mouth. It was soft and tasted like skin. Sam
sighed, but did nothing. She pulled away, his thingy plopping out of her mouth.
"Does that feel nice?" Maybe it was like when she touched her privates.
"Yeah! Nice! More, more?"
She nodded, and swallowed it again. It was harder this time, and kinda bigger.
Not a whole bunch, but still a little bit. She moved her head the way she had
seen her mommy do a few days ago. Sammy sighed and cooed, hips pushed into her
face. "More!" he giggled. "Nice!"
Okay, so it felt nice for him too. She wasn't gonna play if he hadn't liked it.
She pulled away, his thingy falling out of her mouth. It was sticking straight
out, where before it had hung down. His wasn't as big as daddy's, but she was
small, too. Maybe his was the right size for her, then.
"No! More, more! Want more!" Sammy pushed his thingy right against her face.
She sighed, moving back her head. "In a minute, Sammy. I want to do something.
Lay down, okay?"
He sighed, but did what she said. "Kaaaaay," he whined. "But after, more?"
"Yes, but I think this will be fun too."
She took her panties off and put them aside, so that afterwards she could put
them back on. She had put her fingers inside that hole enough times to know
that his thingy would fit. It was as thick as two of her fingers. She had liked
using two more than one.
She sat on him. His thingy didn't go inside her, though, but it felt nice just
having it pressed against her wet skin.
"Ooh!" He giggled, moving his hips. The movement made the tickling sensation
down there more intense. She even gasped and moved her hips in a similar way.
"Dee it nice! So nice! More!"
Nodding, she moved forward, his thingy brushing against her hole. A shock of
tingles struck her and she moaned with her lips tightly closed so it wouldn't
be too loud. Rubbing was nice, but that wasn't what she had crawled into his
crib for, so lifted off of him enough to hold his thingy between two fingers,
and slip it into her hole.
"Ahh!" they both exclaimed, though Sammy did so louder than she did. "More!" He
shoved upward.
Her body tensed with tingles with his movement. "Sammy, you gotta--nnnn--you
gotta be quiet," she whispered, already moving up and down, the way she had
seen her mommy do to her daddy; almost like riding a horse. She could only move
up an inch or so because any more and his thingy would fall out, and she never
wanted it to leave her hole. Each time she sunk down on his thingy, a tiny, but
pleasant, burn down there would get hotter.
"Kay kay," he comically whispered, then immediately started gasping loudly. He
shook his head back and forth, breathing harder with each second. Him thrusting
up just as she sunk down on him shoved pleasure from her privates up her back.
"More," he whispered.
"More," she agreed in a whine. Now she was rocking her hips back and forth
rather than riding him, because he was at the right angle to push against
something inside her hole that had her biting her lip to prevent crying out.
Jerking her hips forward and back had his small peepee rubbing that spot over
and over again.
"Dee, Dee, Dee, Dee," he moaned, each time louder and more high-pitched than
teh last. "Dee! Dee!"
"No, Sam, quiet," she gasped, clamping his mouth shut with her hand, jerking
her hips faster and faster while shocks of intense pleasure burned through her.
She pinched her lips shut to prevent herself from shouting, too.
"Mmmm! Mmmmmfff!" Sammy thrust up, hard, whole body shaking underneath her, his
muffled cried getting higher pitched. He peepee slammed over and over inside
her, and tears streamed down his cheeks.
She was about to ask if he was okay, until something strange happened. A
pressure, an intense, hot, tingly pressure, filled her hole; her muscles
tightening on their own. "S-Sammy, I feel--something's happen--Sammy, I feel--
good, Sammy!" Everything inside her screamed with intense pleasure. Her hand
whipped off her brother's mouth to her own to hide the loud shriek that ripped
from her throat.
Sammy gasped beneath her, jerking up into her, whispering her name over and
over, and she rode his small thingy harder, forcing it to slam against that
spot so that the burning pleasure she had never felt before kept filling every
inch of her body. Her eyes closed so tightly all she saw was white, and all her
muscles tightened and shook, wringing every last bit of those tingles while she
forced Sammy's peepee into her hole over and over.
She had no idea how long it took, but eventually her whole body relaxed. She
still sat astride her baby brother, and his thingy was still inside her,
throbbing, but it seemed smaller and softer than before. She listened for her
parents' footsteps, but it was silent throughout the house.
"That was fun, huh?" She was out of breath.
"Nice nice," Sammy agreed, face red while he gasped for air. "Dee feel nice.
Make me sleepy."
She lifted off of her brother and his thingy plopped out of her. For the first
time in her whole six years of life, she was aware of how empty her hole was.
As if it was made to be filled and unless her brother's peepee was in it, it
didn't feel right.
"Now remember, this is a secret, okay Sammy?"
Rubbing his eyes, he nodded. "Shhhh."
By the time she put on her panties, Sam was sleeping. She, too, was pretty
tired, so she rearranged her nightdress so it wasn't bunched up awkwardly
around her butt, and climbed out of the crib. One thing was for certain though,
she was definitely gonna play this game with Sammy again.
Please drop_by_the_archive_and_comment to let the author know if you enjoyed
their work!