Mabel pulled her sweater up and over her head. She shimmied out of her skirt, walked across her bedroom and stood in front of the full sized mirror that hung on her closet door, looking at herself skeptically.

"It's been years since you were twelve, yet you still have these twelve year old bleeblobs!" Mabel laughed at her own term and brought her hands up to grasp her breasts. While it was true that her breasts weren't as large as some girls her age, she knew she was exaggerating. During puberty, while her friends had gotten their large breasts, she had eagerly awaited hers yet instead she grew taller and taller, seemingly taking up any growth spurts and applying them to height and largely ignoring the curves she desired, to her dismay.

It was mid-summer and Mabel and Dipper were home from college. Both attended colleges near by, so they went home often. Now they were enjoying having the privacy only a room at home can provide.

Mabel jumped as a knock sounded at her bedroom door. She heard the doorknob start to turn.

"Dipper no! I'm naked!"

Dipper burst in with headphones on, BABBA music playing at full volume. He didn't look up until he was already through the door. Mabel shrieked and tried to cover up what she could with her lanky arms.

Dipper looked up and shouted in surprise and almost immediately turned bright red, spreading from the tip of his nose throughout his face. He stood for a minute, clearly in shock, staring at Mabel until he turned around quickly, and started to run out the door. At the door frame he tripped and landing squarely on his face.

Mabel forgot everything and started cracking up. She walked over to Dipper and extended a hand to him, helping pull him up.

"Thanks sis," Dipper squeaked, keeping his eyes directed firmly at hers.

"No problem bro, just knock next time okay?" Mabel giggled.

Dipper stumbled away and closed himself in the bathroom. He was mortified. Poor Mabel. Dipper always felt so comfortable around her he forgot she was a girl, but this incident was a heavy reminder. He leaned on the inside of the bathroom door and put his hand in his pants to rearrange his erection. He sighed, these pants were a bit tight so it made it extremely uncomfortable to have such a large erection.

"Stop thinking about her" he recited to himself for the umpteenth time. He looked down, the erection was still painfully obvious despite his attempts to arrange it. Dipper sighed and left the bathroom, bumping into Mabel in the hallway.

"Oomph!" Mabel grabbed his shoulders and jokingly shook him, "What's your problem with me huh?"

Dipper smiled awkwardly, "oops," he said quietly.

"Woah brother, just kidding there!" She grabbed him and pulled him in for a hug, and gasped. She looked down, then turned quickly, walking away without saying anything. Dipper looked at the floor in shock.

Dipper stood still for a moment, wondering what he should do. His erection wouldn't go away. Mabel was clearly upset, and no wonder with her brother pressing his erection up against her. Even though it was an accident, Dipper felt disgusting. He always had a tiny little crush on Mabel ever since he had gotten over Wendy, but he had pushed it down for years and years. Dipper walked back into the bathroom and closed the door behind him, he needed a cold shower.

Mabel sat on her bed thinking. She heard the shower turn on, and looked up for a minute wondering why Dipper was taking a second shower.

"Poor Dip," she said to herself, "that must have been really embarrassing." Mabel grinned to herself, thinking about the feeling of Dipper's erection pressing against her. She felt herself getting wet just thinking about it. Mabel had been thinking about Dipper in that way ever since she had learned about pleasuring herself. She would lay in bed at night touching herself slowly, picturing Dipper kissing her neck slowly, and tenderly kissing down her neck and biting her nipples.

"ANYWAY," Mabel shouted to bring herself back to the here and now. She looked longingly in the direction of the bathroom. It was more than just sex that she longed for from Dipper. He was her best friend, and her everything. She felt whole when Dipper was around. Could he feel the same way? Mabel had to know.

Dipper brushed his fingers through his hair and felt the water pour down over his head. He didn't hear the door to the bathroom quietly swing open. He closed his eyes and sighed deeply. When he opened them he screamed.

"Mabel?!" Dipper shouted, Mabel was standing in front of him in the shower, naked and smiling at him. He looked over her body, her breasts looked amazing, round and front facing, their nipples were erect. He longed to touch her breasts but kept his hands down, trying to cover up his erection.

"It's okay," Mabel said smiling, she got down on her hands and knees and took his hands in his, she looked up into his eyes.

"I love you Dip. I always have, and you love me too don't you?" She paused for a minute and looked down nervously.

Dipper stared in shock. He couldn't believe it. Was this really happening.

"Y-you.. do?" He stuttered, "I have loved you for an eternity." Tears sprang to his eyes, and he let them run down his face with the water pouring out of the shower faucet.

Mabel laughed aloud, exhilarated. She smiled, "Well Dip, I want to make you feel great. Is that okay?" She didn't wait for a response and took his penis in her mouth. She felt it harden even more and grow in response to her tongue against his shaft.

Dipper gasped, "You don't have to d-" he stopped mid-sentence as a wave of pleasure rolled through him. Mabel was flicking her tongue against the head of his penis.

She took her mouth away and looked up, "Does it feel good Dipper?" she asked. She started stroking his penis with her hand, in long rhythmic strokes. He looked down and nodded, unable to speak as if that would break the spell.

Mabel licked his penis bringing her tongue up and down his shaft as if she was licking an ice cream cone. She continued licking the head as her hand stroked the bottom half in a consistent rhythm that seemed to make Dipper's legs shake in response.

"Oh Mabel, I love you," Dipper groaned. Mabel's tongue felt amazing on his penis, he shuddered with every flick of the tongue. Dipper could feel the rise of pleasure that meant he was about to come. He forced himself to lift Mabel off the floor and bring her to eye level.

"Did that not feel good?" Mabel asked softly, wiping precum off her lips. "I'm sorry," she said. Dipper pulled her quickly into an embrace.

"No Mabel, that felt amazing, but I want to make you feel good too. I have waited so long, and I don't want to wait another second." He felt the tension in his body rise as he lifted her off the ground. She wrapped her legs around his torso as he pushed her back against the wall and brought his lips to hers. Their lips intertangled as they kissed. It was a passionate blur of lips and tongues and Mabel couldn't tell if her eyes were opened or closed, it was only the kiss, only right now.

"I want you inside me," Mabel groaned into Dippers mouth, in between kisses.

"I want to be inside you," Dipper murmured. He lowered her onto his erect penis and she dropped down onto it.

Mabel groaned as she felt him fill her up. She bucked against him as they moved and thrusted against each other, each thrust filling her back up with his huge erection. She kissed his neck sucking and biting, lost in the feeling of having him inside her.

Dipper groaned, "I'm c-coming." He had to lean hard against the opposite wall the keep himself from collapsing as he came into her, thrusting until he couldn't anymore. He lowered her to the ground.

Mabel took his face in her hands and kissed him, "That was amazing," she murmured."

"It's not over yet," Dipper said smiling. He got down on his knees and pulled her close to him. Dipper slipped his tongue through her lips and flicked her clit fast, then put his lips around it and sucked hard.

Mabel gasped and leaned back against the wall, "Oh my god Dip, that feels amazing, I c-can't…" She leaned her head back and closed her eyes, pressing her lips close together.

Dipper sucked and moved his tongue over her lips, circling her clit with a rythym that made her squirm. He grabbed her butt and squeezed and felt her legs tense up.

"Mmmmm, Dipper." Mabel squirmed.

Dipper sped up, moving his lips and tongue faster and faster over Mabel's clit until she was shaking. He kept going, relentlessly licking and sucking.

"Say my name," Dipper demanded in between licks.

"D-Dipper, Dipper, Dipper" Mabel groaned out feeling her body shake as his tongue moved over his clit, she couldn't stop saying his name, like a sacred chant. "Dipper, Dipper Dipper," she shook more violently, as the volume of her voice grew.

"D-d… DIPPER" She groaned loudly as her whole body violently shook and she collapsed slowly to the ground.

Dipper reached up with one hand and turned the shower off, he and Mabel crawled out of the shower and collapsed in a heap, Mabel on top of Dipper kissing his neck.

They lay on the bathroom floor, the only sound that could be heard was the smacking of their lips as they kissed each other, stopping only for breaths and to giggle.

After what seemed like an eternity they sat up.

"Dip, what are we going to do now? Mabel asked smiling.

"We'll figure something out," Dipper responded, reaching over to kiss her gently on the lips. "If we're together we can do anything."