Pinecest(WIP)

        Dipper stared at the dusty, wooden wall as he waited for his sister's breathing to slow down and become heavy. He was ready to begin his nightly masturbation session, but he had to make sure that Mabel was asleep before he could do the deed. Minutes passed as the girl began to snore, giving Dipper the signal to stroke himself in the darkness. He roughly gripped his raging boner, squeezing it a bit as he slowly jerked himself. He mind ran with fantasies about Wendy and her tall, slender body, pressing her small bosoms into the almost-teen's face. He gasped softly as he imagined he saw Wendy lick the tip of his throbbing cock, moaning as she rubbed her moist pussy, his fapping become faster and a bit more frantic as he mentally fondled her ass. Then, as he got ready to enter his crush as she lay on her side, he was interrupted by his sister's voice.

        “Dipper.” He nearly jumped out of his skin, hiding his hard-on as he threw his comforter over his lap. “OH! HEY! Yeah, umm... Just writing some stuff in the journal! Yep!” He chuckled nervously as he tried to slide his diary from under his pillow without his sister noticing, but she just looked at him, her face red and a bit fearful.

        “Yeah, I see that. Looks like.. fun?” The girl's eyes gazed at the small mound sticking up for the sheets, he cheeks reddening as her brother rolled to his side to hide his member from here prying eyes. Smooshing her cheeks with her hands, she looked at Dipper's mortified face as he laid back down, turning his back to her. Mabel waited for a few moments before awkwardly asking Dipper,“Do you need help with that?” Biting her bottom lip, she swung her legs over the side of the bed, sitting as she watched Dipper squirm on the nearby bed. Her heart pounded like a drum as Dipper silently broke out in a cold sweat.

        He couldn't believe that someone was finally offering him something that he had wanted for a while. His hormones had made his nights a living hell as he beat off to his delusions of Wendy, so a chance at some female contact made his boner spring into action. But of course, it just HAD to be Mabel. He had to admit that hid sister was cute, and he did find her a bit physically appealing as she began puberty, but she was still his twin. She was his partner in crime and his best friend, and now she was asking for something as forbidden and weird as this? Hell no. Yeah, the thought of fondling Mabel's chest was popping up in his head, but it was just his dick talking. He had to make the sensible choice before his mind became corrupted by more dirty thoughts.

        Dipper sat up quickly, his face ablaze and his mind fuzzy as he faced his sister. And as soon as he prepared himself to refuse her offer, he noticed Mabel was trying to stealthy rub her panties as Dipper was turned around. She froze and tried to play it off as an itch, but now his dick was raging with desire, and his mind turned to thoughts of fooling around with the girl. Unable to take stop himself, he nodded to her. “Yeah... Yeah, alright.”

Mabel stared back at him for a while, chewing on her hair as her brother scratched his head. Her mind was racing fast with disgust, fear, and arousal as she slowly slid off her bed, inching toward Dipper's. She just couldn't take yet another night of jilling off as she pretended to sleep. She knew they both had needs, and this was an opportunity that very few people had. Climbing in her twin's bed, she decided to push out the thoughts telling her to go back to bed and pretend that this never happened.

        Dipper moved the sheets away from himself to reveal his turgid prick poking against his short. Silently, Mabel pulled down his waistband and watched as his member popped out, hard as a diamond. They both held their breath as the girl firmed grasped it in her hands, feeling the meat stick pulsate softly as she begin to rub it. Unsure of how to proceed, she began to lick the tip of his dick, her crotch growing moist as she began to give her brother a clumsy blowjob. Quickly pushing his pole into her mouth, she began to bob and suckle on as much her mouth could take.

        Dipper had to stifle a gasp at the sensation of his sister blowing him. His sister was constantly kissing and licking his head as she tried to emulate the women she had seen on Grunkle Stan's secret tapes they had found under a floor board. She was doing a mediocre job at giving him head, but the boy was still feeling a great of amount of pleasure from her mouth. His turmoil about messing around with Mabel was now gone, and he decided to continue this foreplay some more.

                The feeling of Dipper's warm length thrusting into her gullet and the taste of his skin as she ran her mouth down the side of his length turned the girl on immensely as she began to roughly fondle his balls. However, unlike her brother, she still felt disgusted as she dragged her tongue on his shaft. How could she be doing this, and to her own twin? I mean, the sight of his hardened dick did turn her on a bit, for some gross reason, but it wasn't him she wanted.  She was in need of some relief, and he just happened to be close enough to provide. And yet, it was her brother she was doing this... this weird thing with. It was all messed up, and she didn't know whether to stop or to keep going, whether to touch herself between her legs and take her time or to hurry up and finish him off. As she engaged in internal turmoil, Mabel didn't notice Dipper reaching down and fondling her flat chest through her long t-shirt. She instantly jerked her head up and saw Dipper's  face change from arousal to a shocked expression as he yanked his hand back.

        “Oh man, sorry!” he hastily blurted out before quickly lowering his voice again as he turned his gaze away from her face. “Sorry, I just kinda grabbed it.” He  nearly hyper-ventilated as he waited for his sister's reaction. He was damn sure that she wasn't cool with him putting his hand on  her like that. He waited for her to silently walk back to her bed and act as it none of this had ever happened, or to whisper to him that he was messed up. Her voice broke the terrible silence. “It's okay, Dipper. Wanna touch it some more?” His head snapped back down to Mabel, who gave him a tiny warm, but nervous grin. Turning his gaze to her chest, he slowly reached down and tenderly stroked her underdeveloped breasts, his fingers brushing one of Mabel's chubby little mounds. The feeling of Dipper's hand on her mini milk mounds instantly disintegrated the fear and disgust she had felt only a few seconds ago, if only temporarily.

        “Uhh... Mmm...” Without even realizing it, she had begun to mewl at her brother's touch. She began to slowly grind the air, her need growing more as she was fondled. She began to push Dipper's rod into her mouth again, her moaning growing muffled as she blew him. In the midst of her lustful murmuring, she heard a tiny whisper that broke her out of her trance. “Come on... Get up here,” Dipper whispered to his sister, as she gently pulled his dong out of her mouth and got up. Confused, she watched him sit on his bed, standing up herself as she saw him awkwardly motion towards her. She took a place next to him, her face beet red as the twins looked at each other. Slowly, Dipper scooted  next to her, his face nearing hers as they both grew closer. In a matter of seconds, their faces were only an inch or two apart, the still air of their bedroom the only barrier between the two. That barrier was soon  broken as the twins pushed their lips together and began to sloppily make out.

        Now, this wasn't a little peck, or the sort of kiss that performed by lovers when they wish to show feelings for each other. This was a messy, almost disgusting clashing of the lips. Even the pair knew it was a bit gross, but whenever they tried separating their mouths, they were instantly drawn back to the kiss.  The two gasped and breathed desperately into each other's mouths as they grabbed each other and began to feel each other up. Dipper began to hump Mabel's leg slowly as she tenderly grabbed his ass with one hand and his hair with the other. The girl panted and softly whined as the boy began to suck on her puffy nipples through her shirt, leaving her chest slightly visible through her shirt. He panted heavily as she felt up his smooth chest,  releasing their kiss for a moment for a cute little belly button kiss before returning for another kiss, cutting down on the amount of slobber swapping when they reconnected their lips.. For a while, they went at it like nervous, frightened puppies, making sure not to hurt each other as they locked lips and explored their sibling's body. And after a good minute such treatment, the two stopped their smooching and laid down on each other, the girl under the boy.

        Each sibling tried to think of something to say now that they had touch each other in such a way, but nothing could be said. Instead, Mabel put her head on Dipper's shoulder, and Dipper began to massage her leg. At this point, they were in too deep to quit. They had already broken a huge taboo, and there was no going back to normalcy after this. And besides, even with the slowly growing fear in their minds, they still felt aroused, albeit aroused, a bit confused, and a bit disgusted. They lay in silence over the course of 30 seconds, neither daring to look at the other in the eyes or to say anything. Then, Dipper began to feel his urges return.. He slowly began to move his hand up Mabel's leg, rubbing on her thigh and the side of her slightly chubby rump. He continually moved his hand from the outside of her ass, to the inside of her thigh, and back out again. After only ten seconds of this, Mabel decided to cut to the chase.

        “Come on, just do it,” she whispered huskily, opening up her legs a bit wider for him. It took Dipper only a second to take her up on her offer, and he pushed his hand back under her nightshirt. He ran his digits on his thighs a bit before sliding his hand onto her slightly damp panties. The girl tossed her head back at his touch, her sensitivity off-the-charts as he stroked her virgin pussy.  This continued for around a minute as Mabel writhed and squirmed at power of his touch. But while she was busy enjoying his hand, Dipper began to crave something else. He lifted up Mabel's shirt, exposing her panties to the room. He stared at the moonlit sight of his sister half-dressed, her chubby nipples gently pushing against the fabric of her nightshirt, her underwear dotted with her juice. On any normal night, he would simply look away as fast as he could and yell at her to pull her shirt down. But not this night.

        This night, he pushed his head between legs, cautiously lapping at her smooth thighs.

        This night, he slid her panties down to her ankles, giving her a quick look to make sure it was okay. She was too busy massaging her chest to look back, so he took her silence as an OK to continue.

        This night, he stared at her moist slit with a rush of excitement, his boyhood throbbing in his hand all the while.

        And this night, he peeked his head between her legs and, after staring at her smooth, beautiful genitalia, began to give her pussy a few well-placed kisses.

        Mabel managed to grit her teeth and cover her mouth just in time as her throat emitted lusty cries of pleasure. Hearing his twin's reaction, he dug in deeper, kissing her lower lips constantly as he began to explore her with his tongue.