
Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/6975031.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      F/M
  Fandom:
      Gravity_Falls
  Relationship:
      Dipper_Pines/Mabel_Pines
  Character:
      Dipper_Pines, Mabel_Pines
  Additional Tags:
      reverse!pinescest, Sibling_Incest, reverse!verse, im_so_bad_at_tagging,
      Strap-Ons
  Series:
      Part 2 of Alpha_Twin
  Stats:
      Published: 2016-05-26 Words: 1762
****** By My Command ******
by starsinjars
Summary
     Mabel doesn't like the fact that Dipper has all the control in the
     sexual part of their relationship, and decides to fix that.
Notes
     A/N: They're 16. First time writing something like this lolz.
See the end of the work for more notes
o-o-o-o-o
"I have a problem, dear brother of mine."
Dipper turned to his twin sister Mabel, lowering the voodoo doll he was working
on with his telekinesis that came with his half of the pendant. "And whatever
would that be, my sweet sister?" he asked, frowning at Mabel's leer. He did not
like the little twinkle in his sister's eyes. She was planning something, and
that something might not benefit him.
"I was thinking. It's not fair for you to have all the power in this so called
relationship of ours," she said as she conjured up a box. Dipper focused on the
box, and Mabel grinned as she set it aside and started to remove her collar
ribbon and vest.
Dipper smirked back as he loosened the pendant resting on his neck and
unbuttoned the top of his shirt. "Really, sister, as if I control anything
without you in this twisted bond we call a relationship." He made a reach for
his belt.
Dipper paused as his hand started to glow blue. "In this aspect, you do." Mabel
narrowed her eyes as she lowered her hand, the blue light fading. She slowly
made her way to her brother. "And that does not go well with me."
Dipper raised an eyebrow as Mabel came face to face with him, a soft but
sinister smile gracing her lips. "Oh?" he hummed, smirking in reply. "And what
are you doing to do about it?"
Mabel snatched his half of the pendant, snapping her fingers.
"What –"
Dipper couldn't finish or take back what Mabel took as he was immediately
restrained by ropes and tied down to a chair. He sagged into the ropes, knowing
it was futile to fight.
Mabel winked, tossing Dipper's pendant in the air a few times before pocketing
it. "I have a few ideas." She climbed to sit on Dipper's lap. Mabel then slid
closer to her brother's chest and placed her finger under Dipper's neck, nails
slightly etching into his skin as she redirected him to look at her.
"Eyes on me, brother. Only on me," she murmured as she slowly undid Dipper's
belt buckle and tugged down his pants. Mabel giggled as she undressed her
brother, running her fingers along his now bare chest. She brought her lips to
his neck, biting hard.
Taking a deep breath, Dipper tried to focus his thoughts. He'll play this game
of his sister's design, but he won't make it easy for her. Seeing that her
brother was lost in thought, Mabel's fingers pinched his nipples, making Dipper
squirm. "What's in the box?" he asked as he tried to steady his breaths.
"Ah, the box." Mabel smiled innocently, but both knew it was an act. "You'll
see soon enough." She unbuttoned her own top to reveal her black lacy bra
underneath. Unclipping it from the back, she pushed herself forward so that her
breasts would be in front of Dipper's face.
"You know what to do."
With just a moment of hesitation Dipper stuck out his tongue, twirling around
one of Mabel's nipples before sucking it gently. He quickly alternated between
the left and right, making sure that they were both coated in saliva and perky
from the simulation. She sighed as she eased herself closer, keeping the warmth
only between the two.
Mabel knew Dipper's hands were twitching, wanting to touch her supple flesh.
Not that she could blame him - that was their usual routine, with Dipper in
control. Not this time, however. She tightened the ropes, causing Dipper to
pull back. He hissed, his mouth making a popping sound as Mabel grabbed him by
the hair.
"Not this time, dear brother. Not this time," she murmured. She ran her fingers
down Dipper's face and tipped his chin towards her face for a kiss. "This time,
we're playing by my rules."
It started sweet, but quickly turned spicy as Mabel bit her brother's lower lip
hard enough to draw blood. Dipper moaned, the bloodplay making him lightheaded
but horny. "Mabel," he breathed as his sister licked up the blood, but not
before some dripped down his chin.
Mabel licked her red lips, grinning before going back for more. Her fingers
traced along Dipper's chest, going lower and lower before finally reaching
Dipper's hard cock. She palmed it, and didn't miss the hitch in Dipper's
breathing.
Mabel grinned as her brother slowly became undone by her design. She softly
grinded against it, causing for her brother to squirm. His breaths became
unsteady, whole body twitching, and soon enough Dipper was trembling by the
slightest touches.
"Funny, how easy it was to rile you up," his sister commented, frowning
slightly. "It's almost too easy." She paused.
Dipper smirked at his sister's hesitation. "Isn't this what you wanted, sweet
sister?" he asked as Mabel suddenly took hold of his dick and squeezed it
tightly. He took a breath. "Me undone by your command?" he asked, voice
slightly unsteady.
"No," she replied, twirling her finger around the head. Dipper let out short
pants as she slowly began to move her hand up and down the shaft. She bent
forward to her brother's ear, placing her hair behind her own ear.
"I want your total surrender."
Mabel pulled back and snapped her fingers. She jumped off her brother's lap as
the chair Dipper was sitting in broke to pieces. Dipper fell to the floor, no
longer restrained, but all attention was on the box his sister held in her
hands.
She tossed the box in the air, suspended by magic, and held her brother down to
the ground. She took Dipper's hands and guided them up her legs. Mabel moved
Dipper's hands to her panties, and they both groaned after feeling just how wet
she was.
"Dipper," Mabel moaned as her brother pulled off her black lace panties and
tossed them aside. He grinned as he caressed her inner thighs.
"Mabel," Dipper replied breathlessly, moving his fingers around her clit. He
bent his head and soon was licking her wet pussy, eliciting a gasp from his
sister.
Dipper ate her out while Mabel stroked his cock, the touches and simulations
bringing them closer to the edge.
With a snap of her fingers, Mabel placed a ring on the shaft before she lowered
herself onto Dipper's hard cock. He groaned as she sighed, finally feeling
full. When she began to move to ride him they moaned, both lost to a rhythm
that only they could hear.
Dipper was getting close, Mabel could tell. Not that he could come with the
cock ring she placed, but she knew she was getting close as well. He didn't
have as much stamina as she did to go for another round, and there was still
the present. Mabel was soon hitting her sweet spot. She moved faster, rougher,
and was soon riding out her high before she pulled herself off of her still
aroused brother.
She quickly regained her composure and smirked. "I think it may be time for
your present," she whispered, gesturing with her free hand to summon the box.
Dipper paused, finally about to have his curiosity satisfied. Mabel took her
time lifting the lid, slowly reaching inside and pulling out a golden double
ended strap-on.
Dipper's eyes widened, then narrowed. He looked… nervous. Mabel snickered.
"Afraid, brother of mine?" she whispered as she caressed his face with the
object. She didn't wait for a reply as she shoved it in his mouth, planning to
use the saliva as lubricant. She lubed up one of her hands with a snap and
prodded near Dipper's entrance.
Dipper found his voice as Mabel removed the strap-on from his mouth. "Are you
sure you want to do this?" he asked, a slight tremor in his voice that everyone
but Mabel would have missed.
Mabel grinned. "So you are afraid." She forced two then three of her lubed
fingers inside and scissored them, making Dipper squirm. "Don't you worry, dear
brother, I'll be gentle as you are with me." She removed the fingers and moaned
as she inserted her end of the strap-on. She placed her hands on Dipper's
wrists, readied her position and removed the cock ring before pushing herself
inside.
Dipper let out a grunt of pain that trailed off to become a groan, and Mabel
waited for him to adjust before moving. She moaned at the feeling of feeling
full and filling someone up at the same time. When she began to move, Dipper
moaned at the feeling and Mabel quickly found that sweet spot of his. She
pounded into him, riding the power high of her actually fucking her brother
instead of the other way around.
Dipper found it difficult to think, to breathe, do anything that took his
attention away from his sister. Mabel closed her eyes as she slowly started to
lose control, and Dipper smirked as she lost her composure completely. As much
as he loved fucking her, there was some kind of thrill of her fucking him.
Probably because they were breaking yet another taboo about their relationship
together. Soon enough he could feel that familiar coil in his belly about to
burst and closed his eyes.
Mabel trailed her hand along Dipper's torso and continued to thrust as she
kissed her brother's lips. "You look so beautiful under me," Mabel murmured,
loving the expression on his face. Dipper kept his eyes shut, biting his lips
to keep himself as composed as he could with his sister fucking him. He didn't
want to admit that he enjoyed it, but Mabel knew that if she was having this
much fun Dipper wasn't as miserable as he'd like her to believe. She could feel
herself about to come again and only gave Dipper warning when her thrusts
became more erratic.
Mabel moaned as Dipper wrapped his arms around her neck. He pulled her in
close, about to capture her lips with a kiss. He froze at the last second and
shuddered, pulling his sister tight and close to him as he came. Mabel paused
in her thrusts, shuddering as she came as well just a few moments after Dipper.
Mabel grinned as she snapped her fingers to make the strap-on disappear. "That
was fun. We should do this again," she murmured softly. They picked each other
up from the dirty floor and she handed her brother back his half of the
pendant.
Dipper just snatched back his pendant from her in response, but Mabel caught
that little twitch of his lips and knew that he agreed.
o-o-o-o-o-o-o-o
 
End Notes
     A/N: Welp I tried. Thanks for reading!
Please drop_by_the_archive_and_comment to let the author know if you enjoyed
their work!
