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Fistbump 2: Unspeakable (a Pinecest story)	By : Edward_or_Ford Category: +G through L > Gravity Falls Views: 21285 -:- Recommendations : 0 -:- Currently Reading : 0
Disclaimer: I do not own Gravity Falls or its characters. I will not earn any money from this story.

Chapter List
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Wednesday was taking altogether too long to arrive for Mabel’s liking. By Tuesday, the previous few days had been a fearsome test of her long-term acting ability. She had successfully deprived herself off any outwardly-visible signs of affection for Dipper, but it had been a struggle. It seemed such a cruel hand to be dealt, to be so near to the love of her life, and for them to be forced to only be brother and sister.
She idly remembered a joking comment that Dipper had made the evening they had returned from the pivotal weekend in Portland back to Gravity Falls, just over two weeks ago. Dipper had offhandedly said that he almost wished that they didn’t have to live together: that it might be easier to not have to see each other all the time, and be somehow less painful. Part of Mabel was actually starting to consider the pros and cons of such an idea, though the rest of her hated that part for having such thoughts.
Still, questioning her decision of how to adapt to her new lot in life never occurred to her. Originally, the plan had been that both of them would try to actually put their feelings on the back burner, that they make an attempt to truly cool their emotions for one another until they were eighteen. Mabel had tossed that plan away the very night they arrived home, deciding instead to hide her feelings instead of losing them. Even the terrible feelings of violation from last week had not budged her opinion that she would never, ever deny to herself her love for her brother.
Dipper, on the other hand, was more pragmatic. To him, actually losing Mabel from his life was the worst possible outcome. He never meant the comment about not living together, as he would rather deal with the discomfort of living together platonically than to be separated. He also knew the danger of being separated forcibly, rather than voluntarily. And that could happen anytime they made a mistake. Dipper knew that risk avoidance is all about not allowing an event to happen in the first place. To that end, he still agreed with the advice that Grunkle Stan had given them just before they came home: it would be best if they actually tried to end the romantic part of their relationship. Difficult? Yes. Painful? Without a doubt. But impossible? No. Not impossible.
Unless, of course, your sister completely abandons that plan immediately after you arrive home, and finding opportunity to talk about these things becomes really, really difficult!
Dipper found himself stuck in between. He didn’t have the acting ability or the emotional stomach to go the full-Mabel route, not without making a mistake. But he also couldn’t just completely let go of his intense feelings, a proposition made even more difficult by Mabel apparently insisting on Wednesdays being the designated sex nights. He resolved to attempt to turn everything he felt about Mabel “off” every other opportunity he had, and see how that worked.
So it was on Tuesday night, as the Pines family was eating supper. Their parents always insisted on eating together at the dining room table whenever possible. After saying prayers and being thankful for the meal, they started discussing their day as they ate.
While their mother and father were talking about one of their mother’s clients, Mabel noticed Dipper slouching in his seat directly across from her. Figuring his legs were probably stuck out in front of him, she couldn’t resist the opportunity to play “footsies”. She moved her foot to find and caress his legs beneath the table.
At the first contact, Dipper thought it might have been an innocent touch, but that possibility went out the window as he felt Mabel’s foot slide up, then down his calf. He stared intently at Mabel, but she was dutifully filling her fork with food from her plate. I’d be impressed with her multitasking if this weren’t such a serious situation, he thought to himself.
He straightened up in his chair and pulled his legs back, ending the tease. When she threw him a questioning look, he shot a warning look back. He felt a little bad when he saw a hurt expression cross her face, then it was gone as their mother asked her a question about her school day.
Dipper hoped that they would have a chance tomorrow night to talk about how taking an unnecessary risk could be really bad for their relationship.
Mabel hoped that they would have a chance tomorrow night to talk about how taking a minimal risk could be really good for their relationship.

The twins had a good day at school the next day. Dipper, Ezra, and Anthony made plans to start a new informal school club for role-playing game enthusiasts. They figured that they may as well stake their claim officially as the new school nerds, since it would be less uncomfortable to proclaim the title themselves than to be labelled after the fact by the other idiots at school.
Mabel and her friends all excitedly had auditioned for the school’s drama club. The school was planning on a musical production of “Hairspray”, and although Mabel had to admit that her singing skills, though undoubtedly enthusiastic, were somewhat limited, she still eagerly anticipated the chance to participate. Mostly though, she silently squirmed in anticipation of the evening to come at home with Dipper.
Per routine, the twins walked with Anthony and Sandra. Against routine, Anthony and Sandra found something to talk about separate from Dipper and Mabel. Anthony’s brother had played the original John Waters movie of “Hairspray” for him, while Sandra had seen the musical, and they were comparing the differences between them. They laughed over which guy at school should play the part of Tracy’s mother. A natural spark formed between the two of them, which Mabel found incredibly cute. Even Dipper noticed them, and envied that if they were to get together, they wouldn’t have the obstacles he and Mabel faced.
When they got home, their mother was home as per normal, but was also occupied with client calls as usual. She worked from home out of an office that the family had converted from what was supposed to be a guest bedroom on the opposite side of the house from the other bedrooms, and presently, as on most days, was engrossed with one, or possibly many clients. Their father was still at work, as he typically was until almost six. When the twins came home and passed by the office, their mother waved silently with her ear glued to her phone.
Before Dipper could get distracted by a video game or turning on the computer, Mabel grabbed him by the hand and dragged him to her room. She shut the door, then pinned him to the back of her door and urgently pressed her lips onto his, while snaking her arms around his neck and back and pulling him close.
Dipper was unprepared for the assault, but decided they were safe enough and gladly submitted. His own arms were quickly around Mabel’s body, and his tongue found hers. Both of them were getting wound up, excited despite the fact their mother was under the same roof.
Mabel felt the front of Dipper’s pants, moaning into his mouth at the lump that she knew was forming there. She pulled him across the room to her dresser, where a towel was waiting, left there that morning in anticipation of this moment. She grabbed the towel and pulled Dipper back over towards her bed. Mabel dropped the towel there and started fumbling with the button and zipper on Dipper’s pants. Dipper broke off the kiss in alarm, but before he could object, Mabel breathed “Just trust me! And be quiet!” then she continued her work releasing his penis from his pants. It was fully erect and ready as she pulled his pants and underwear down to his knees.
She then spun him around, making Dipper face the bed, and reached around to grasp his penis with her right hand while she held his chest and right shoulder securely with her left arm. Mabel then started jacking back and forth quickly, feeling Dipper’s body tense with pleasure. A strangled grunt of arousal emitted from his throat, followed by desperate panting.
“Pick up the towel,” she breathed into his ear as she continued his stimulation, “and get ready!”
Dipper understood, managing to grasp the towel and hold it in front of himself as Mabel maintained her rapid movement on his sensitive organ.
Seconds later, her efforts reached fruition. Dipper suddenly tensed his whole body, then exploded into the towel, while making pitiful noises that he muffled within his closed mouth.
Mabel stopped her masturbation of her surprised twin, and held him close to herself. He continued panting slowly, amazed at what his sister was able to do to him so quickly. He whispered his approval through quiet gasps “That … was awesome! … I love you!”
“I love you, too!” she murmured back, turning Dipper back around to face her and pull him into her arms, clutching his heaving body. Then she suddenly put her lips to his ear. “That’s Round One!” she rasped. “You owe me Round Two! I’ll see you later, Sir Dipshit!”
With that, Mabel released her grip on Dipper and strode to the door. She did crack the door first to make sure no parents were waiting on the other side, then with an evil grin flung the door open. Dipper frantically started pulling up his pants and underwear while Mabel watched with satisfaction, then she sauntered out to the kitchen to prepare an after-school snack, leaving her bedroom door wide open.
Dammit, Mabel! Dipper cursed inwardly, finishing doing up his pants. You can’t keep doing things like that! We’ve got to be more careful!

Soon afterward, the family had eaten their dinner, and the twins’ parents left for their bible study. The car wasn’t even out of the driveway when Mabel sprinted to her room. “Be right ba-aack!” she called out, then slammed her door.
Dipper walked over to the living room sofa and sat down nervously. He wondered to himself what his crazy sister had planned for him, knowing that she’d been concocting something since last weekend. The thinking itself ate up any time he had to prepare.
A few minutes later Dipper had his answer. He heard Mabel’s door open, and then odd-sounding steps coming down the hallway. He turned to watch as she appeared from around the corner.
His mouth dropped open. Holy shit! he thought. It was the same thought and facial reaction he’d had in Portland when he’d seen Mabel in the same outfit. Well, some of the same outfit.
Mabel’s smile was huge and dazzling as she posed provocatively for Dipper with her hands on her hips. She had dug into her closet for some of the clothes she hadn’t worn in some time. He recognized the black beret perched neatly on top of her head. She had on her darkest sunglasses. Her old black leather jacket was a bit too small and was unzipped, revealing what she wore beneath.
Which, as Dipper observed in stunned silence, was not much. Mabel proudly showed off the bikini, the bikini, that she had briefly teased Dipper with in Portland. Also black, like the rest of her ensemble, it was smaller than any swimsuit either twin had ever seen. The top consisted of two tiny triangles of fabric that managed to cover only the barest portion of Mabel’s small breasts, connected by skinny elastic threads. The thong bottoms were a slightly larger triangle connected together by the same impossibly skinny elastic. The contours of her camel toe were clearly defined, and it was obvious that she shaved her pubic hair.
Completing the look was the black high heel shoes she had purchased with the bikini. They successfully forced Mabel’s posture into a sultry stance, so that she arched her back and thrust her breasts out.
Mabel was having the time of her life. I get to play dress up, and wind up Dipper at the same time! What combination could be better? Wait’ll he gets a load of this! She struck another pose, leaning her shoulders back against the wall, raising one foot to rest against the wall behind her and raising her arms above her head, spreading out the open jacket. Her smile widened even further as she watched Dipper’s awed expression. She slowly took off her glasses and dropped them to the floor, then removed the beret and tossed it playfully to Dipper on the sofa.
She posed again, this time turning and bending over at the waist to lean forward against the wall, arching her back and prominently showing off her essentially naked behind while supporting herself on her forearms. She turned her head back to Dipper and slowly licked her upper lip seductively. Mabel couldn’t get enough of the way her brother was so obviously turned on by her.
Mabel was also getting herself worked up to a fever pitch. She had only masturbated once in the past week, and that was Saturday afternoon after she and Dipper had made up. Days of unreleased sexual tension were struggling to escape. She wiggled her index finger deliberately, beckoning Dipper to come join her.
In a daze, Dipper slowly made his way to Mabel, in the back of his mind thankful that she was staying in the back of the room, largely away from the big window that looked out onto the street. He approached her inviting ass, a small moan coming from his mouth as he palmed both of her cheeks gently. Mabel had her head turned back toward him, an aroused and seriously overjoyed look on her face. She actually likes doing this! Dipper saw. She’s not demeaning herself for my sake. She wants to be the tease!
He slid his hand up her back beneath the jacket as he moved to her side. He cupped her face with his other hand and kissed her deeply, satisfied humming emitting from both of them. Dipper was thinking that this was a little awkward, both of them bent over with their faces pressed up next to the wall, so he tried to guide Mabel to straighten up.
Mabel pulled away and refused to move. “No,” she said quietly but firmly. “Right here!” Her voice grew huskier. “Right now!”
The tone and intensity of her voice made Dipper’s penis snap even more to attention. He kissed her hard on the mouth, then maneuvered his head under her to kiss and run his tongue down the front of her body, down to her belly button. He moved the hand that had been up her back down over her butt, then slowly between her legs, moving the thong aside. As he straightened up to move behind Mabel, he gently found the entrance to her vagina and eased his middle finger inside. Mabel tensed in anticipation, and Dipper was surprised she was already so wet. He unfastened his pants, for a second looking back to the living room window, and wondered if anyone could see in if they were trying.
Oh, hell, who am I kidding? he thought quickly. There’s no way I’m stopping now!
Mabel was beside herself. Dipper’s trail of kisses down the front of her body was just torture. Being naughty was making her hornier than she could stand! After his pants and underwear were at his ankles, Dipper started to pull down at the strings of the bikini bottom. Mabel whined back to him, “Don’t bother! Just do it now!”
Dipper didn't need to be told twice. Pulling the thong aside again, he used his other hand to aim his penis to her slick opening. When he felt himself starting to slide in, he grasped Mabel's hips and pushed himself in with a single thrust, holding himself in. Mabel loudly moaned her approval. "Please!" she gasped urgently, unfocused eyes staring straight ahead to the wall. "Ooh, please, Dipper! I need this so bad!"
Dipper smiled, cocked his head to the side with raised eyebrows, and muttered “Oka-ay!”
Gripping harder to her waist, Dipper started fucking Mabel vigorously. They had done it “doggie” style once before, but never standing up, and never with as much urgency, so he slipped out a couple of times when he pulled back too fast. He wasn’t pushing in fully, because he thought he would slam Mabel’s face into the wall. But soon he was pulling back on her with his hands, coordinated with his thrusts, so she wouldn’t be hammered forward so hard. The living room was now filled with the sound of Dipper’s pelvis smacking solidly and repeatedly into Mabel’s butt, mixed with the groans of two very aroused teenagers.
Mabel loved the feeling of Dipper's penis slamming into her, but this position was getting tiring. Her grunts started to sound frustrated as she struggled to build up to her climax.
Dipper was in no hurry, his prior orgasm having taken the edge off his need to come. He could feel the tickle, and knew he could come again if he tried, but he wanted to concentrate on satisfying his sister. He pushed in hard, bent forward over Mabel and used his left hand against the wall to support his weight, his fingers finding hers and intertwining with them. With his right hand, he reached around Mabel's waist, and his first two fingers found her clitoris. As he started rubbing her sensitive button, he used his wrist and forearm to pull her back into himself, and began to thrust in shorter, but much faster, strokes.
He knew immediately that he was on the right track. Mabel's noises became louder and higher-pitched. Dipper felt her pushing back against him on each thrust.
"Oh, God!" Mabel cried, gripping Dipper's fingers tightly in her own. "Don't stop!" Dipper tried to increase his pace, matching the speed of his hips to his fingers' massaging of her clitoris.
Mabel lowered her chin to her chest and let out a strangled wail as a tremendous orgasm smashed over her. Dipper lovingly kept up the rhythm, continuing to stimulate Mabel through peak after peak of pleasure. She deserves every ounce of joy I can give her, he thought happily.
After what seemed like forever, it became too much for Mabel. Her legs gave out beneath her, and Dipper couldn't hold both of them up. The twins collapsed into a pile on the floor, Mabel curled up and gasping helplessly for breath, while Dipper rolled over and sat with his back to the wall while panting and laughing at their clumsy predicament.
Mabel had drawn enough air to turn her head and gaze at her lover. “Hot … effing … Belgian … waffles!” she managed to get out. She gave him a salute, then reached out with her hand, and Dipper grasped it. “You, sir ... are incredible!” she proclaimed with an exhausted smile, shaking his hand as if in congratulations. “Don’t you ever stop making me feel this way!”
“I promise!” Dipper replied. “I love you, Mabel. I’ll do anything for you!”
“Yeah? Good … I’ll remember that!” Mabel said mischieviously, still panting. “Start by explaining … why this,” Mabel reached over and lightly grasped Dipper’s slick penis, “is still hard! … What happened to Round two?”
Dipper made a little gasp as Mabel started gently jacking him. “What can I say? You did a …” he was forced to pause for another long intake of breath, “... much better job with Round one than I’m used to!” He paused, and stroked her cheek affectionately. "Plus, I held back a bit ..." closing his eyes and gasping again, "to make sure I made you feel good first." Dipper's voice went up at the end as Mabel's hand continued its work.
Mabel got to her knees and crawled over to Dipper. She held the back of his head with her free hand and kissed him deeply, while slightly speeding up her stroking of his penis with her other hand. He moaned helplessly into her mouth.
"No more holding back," she ordered quietly. She released his penis and cupped his scrotum, while giving him a smoldering stare. "I want all of this! Understood, Sir Dipshit?"
"Aye, Captain!" Dipper grinned, not caring that he had mixed their role-playing metaphors.
Mabel planted another kiss, then got up off of her brother. They got to their feet, Dipper managing despite his ankles still being anchored together by his pants and underwear. Mabel laughed as he half-shuffled, half-hopped his way behind her down the hallway, catching up to her outside his room.
He embraced her waist and inhaled on her mouth, while starting to guide them through his doorway. But Mabel felt a tiny prick of apprehension, which she knew was linked to last Wednesday night, and what happened the last time she was on Dipper's bed. She subtly turned them back around to her room instead.
Dipper yanked down the leather jacket off of Mabel's shoulders, followed by Mabel pushing his shirt up over his head. He fumbled with the knots of the bathing suit for a few moments, before she told him to take care of his own pants, socks, and shoes, and she'd handle the swimsuit and her stilettos. They were quickly naked and back into each other's enthusiastic arms, necking with abandon.
Mabel pulled Dipper backward to her bed, leaning back so Dipper would flop on top of her. Giggling, they fumbled their way higher on the bed, then Mabel spread her legs wide and reached for Dipper's penis. He let her pull him down to her, lining him up with her vagina.
He pushed into her easily as their mouths and bodies merged again, accompanied by incredible feelings of satisfaction and completion by both of the siblings.
Dipper moved his hips slowly and gently, humming happily through their passionate kisses, his arms holding her close. Mabel wrapped her legs around Dipper's behind, rocking in slow rhythm with him, gliding her hands over his whole body.
The twins simply made love, tenderly attempting to somehow fuse their bodies and souls together. They took their time, unabashedly free for the moment from the world that made their love forbidden.
This is just so natural, so perfect! Dipper thought. How could this possibly be wrong?
I can't imagine loving anyone more, Mabel thought, or being any happier! I don't want this moment to end!
Eventually, their breathing became heavier as the pace of their dance gradually quickened. They broke their kissing to just stare in awe into each other's eyes, their sweating foreheads pressing together. Their desire built, their bodies moving together more fervently, ragged breaths joining passionate noises of pure adoration. They could feel that they were getting close, and they knew that they would climax together. And still they couldn't stop gazing at each other.
They both knew it was coming, and that by now it was corny, but they didn't care because it was right. "I love you so much!" they panted urgently to each other in unison. Smiling in unbelievable happiness, they began to press their mouths together again, ready to hold each other tightly through the exquisitely perfect finish that would come in just a few moments ...
… when they heard the sound of their father’s voice at the other end of the house, as he came through the side door. "Hey kids! We're back! Bible study was canceled."
Dipper and Mabel froze, gaping in horrified shock at Mabel's wide-open bedroom door, then at each other.
"Kids?" came their father's voice again.
"Shit!" they whispered desperately in unison.
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Fistbump 2: Unspeakable (a Pinecest story)