Dipper felt horny as he sat in his room at home. That wasn’t too surprising, given his condition. He may have only been twelve, yet he’d been born with a… Well, he hesitated to call it a defect. Granted, it could get grating sometimes, but even when it got on his nerves, Dipper loved his condition with all his heart.
“Hehe, whatcha thinking about, bro-bro?” Mabel asked with a broad grin over her cute face. Her back was to her brother, like always. So she pulled her long hair off to the side and lifted her sweater to reveal her bare bottom. “Is it my tush? I hope it’s my tush.”
“Well, it is now,” Dipper conceded. He knew what his twin wanted, so he set his hand on her bottom, making both siblings tense from the contact. Mabel’s ass was so soft, and it was impossible not to squeeze. Dipper then wedged his thumb between her cheeks, prying them apart to expose her pucker. “You ever wonder why you have a butt hole?”
“I think you know my answer,” Mabel replied over her shoulder.
“Something crude?”
“You know me so well.”
“I mean it, though,” Dipper said as he idly fondled his sister’s young ass. “You don’t poop. You don’t even sit, so what’s the point of having a butt?”
“Ugh, you think too much, bro-bro,” Mabel groaned. “Obviously, I have a butt, so you have something to play with until my boobs come in.”
“Implying that I’m gonna wait?” Dipper retorted as both hands reached to cup his sister’s budding chest through her kitten sweater. “Hmm, still flat, but you’re definitely developing,” he appraised.
“Nnngh, yeah, squeeze me,” Mabel moaned, leaning her back to Dipper’s chest as he sat on their bed. Her cheeks grew flushed as her breathing became ragged. “S-so hot. K-keep rubbing. Oh, like that!”
“Like this?” Dipper clarified, pinching her nipples the same way. Mabel’s moan sent tingles through his erection, just as always. His hips began humping, shaking his sister as he held her steady. Then, knowing that Mabel wouldn’t calm until they came, Dipper reached under her sweater to finger her pussy. Despite doing this countless times before, his fingers contacting her wet slit never failed to make the siblings jump as volts of pleasure shot through their systems. Dipper adjusted quickly as he started more earnestly fingering his sister. He felt her sex spread as he probed ever deeper. The young boy felt his sister’s stirring insides as keenly as she did.
Likewise, Mabel’s whole body burned from Dipper’s burning arousal. “That’s it, bro-bro. Ngh, fuck your pussy! Ugh, I feel it burning. Gah, I’m so hard right now!” Finally, Mabel could take no more, and she threw off her sweater. Now utterly nude from Dipper’s trousers and up, Mabel wrapped her arms around herself. The cool air felt refreshing against her hot body as her hands ran across her sensitive skin. It was electrifying when she touched her breasts or helped her brother finger their pussy. However, at this point, Mabel was so turned on that touching anywhere felt fantastic.
As he felt a stirring in his balls, Dipper sprang out of bed. He continued holding Mabel to his chest as he rushed to the bathroom, knowing what was coming. It had been irresponsible not to start in there. Although, if they made a mess, he had every intention of blaming his sister. His parents would probably buy it, given that she was the hornier of the two. Finally, at the toilet, Dipper lifted the seat and pointed Mabel’s face down into the opening while continuing to finger their pussy and rub her breast.
At long last, the twins came. A geyser of jizz erupted from Mabel’s mouth, straight into the porcelain throne. After years of expelling his cum, she’d developed excellent aim. Both twins grabbed the nearby counter to steady Dipper’s wobbly legs as they continued ejaculating from her mouth. Several seconds passed before she finished, and Mabel turned around with a tired, satisfied grin and a messy mouth.
“So, are we good?” Dipper asked as he felt the emptiness in his sister. At her affirming hum, he grabbed a tissue and wiped clean his sister’s mouth, which was also his cock slit.
Dipper and Mabel were conjoined twins, but not in the usual way. Their condition was extra rare. Essentially, Mabel was Dipper’s penis. Her body grew out from his pelvis, and their internal nerves and organs intertwined in a way that made her his penis. They peed from her pussy, pooped from his butt, but they orgasmed from Mabel’s mouth. It was bizarre and led to years of uncomfortable staring from strangers as the siblings just wanted to live their lives.
Further, the condition, which Mabel affectionately referred to as being a penis person, came with other side effects. For one thing, her skin was incredibly sensitive, and she had to wear custom-made sweaters that were soft enough for her skin or nothing at all. Luckily, Mabel was a free spirit, which was a nice way of saying shameless. That went well with the other symptom, which boiled down to intense horniness. Being a penis meant Mabel had what she considered penis instincts. That is to say that she wanted to be inside of wet and warm holes almost all the time. While near-constant horniness got annoying, this was sort of a mixed blessing, as the Mabel carried an ID that excused her going inside almost any orifice she wanted until she was satisfied. Once people understood this was to alleviate her medical condition, most people were hesitantly willing to help. Ironically, this led to Mabel becoming rather popular with the ladies, who often viewed Dipper as the dead weight of the pair, even though he controlled their legs.
Unsurprisingly, Mabel was bisexual. She liked guys as much as girls, if only for a quickie, but tried to stick to girls for Dipper’s sake. She worried about him. Despite being literally fused at the hip, her brother was a loner. If his sister-penis didn’t lead him around to one mess after another, he’d probably never leave the house. And while she was fine with her condition as a penis, she sensed that Dipper longed for more independence, and probably a connection with someone else. He’d never say so out loud to spare her feelings. However, when you spend every waking second with a person, you tend to pick up on a few things. Mabel wished she had a way to pull him out of his shell.
Luckily, summer arrived, and Mabel got her wish. Their parents sent them to Gravity Falls, Oregon, to stay with their Great Uncle Stan, whom she immediately dubbed their grunkle. The old man ran a tourist trap in the sleepy town called the Mystery Shack, which hosted all manner of oddities. Once the aged swindler stopped trying to set the twins up as an exhibit (for now), he showed them to their room in the attic before putting them to work in the Shack. There, they met the other staff. Soos, the handyman, was a loveable goofball, but very skilled with his tools. Wendy was a disinterested redheaded teen who worked the gift shop. Although, ‘work’ was a rather loose term in her case, as she did everything she could to duck out of any assignments from Stan.
Mabel was excited to spend all summer in the woods surrounded by colorful strangers. However, Dipper seemed even more reluctant than usual to engage with others. He kept saying something seemed off about this place, like there were eyes in the woods or something. Mabel liked the idea of meeting such new and interesting people, hoping they could have a romantic encounter that was more than just a fling.
1 Stan sends the twins to set up signs in the woods
2 Mabel starts chatting up the tourists
3 Dipper chats with Soos
4 Wendy tries not to be rude while asking about the twins’ condition
View Portfolio
Visit Notebook
Send Gift Points
Awards
Badges
Send Email
Community Newsfeed
General Discussion
Sponsored Items
Book of Trinkets
Static Items
Books
Groups
Interactive Stories
Audio
Campfire Creatives
Community Notes
Crossword Puzzles
Documents
Folders
Images
In & Outs
Madlibs
Photo Albums
Polls
Product Reviews
Quizzes
Survey Forms
Web Pages
Word Searches
More by this author