Chapter 1

Not gonna lie, first chapter is far more smut and angst and stuff than actual story. But I promise it'll speed up next chapter! :)

"Oh, but your love is such a swamp/You don't think before you jump/And I said I wouldn't get sucked in/This is the last time" - "This is the Last Time" by the National

Under the flickering bathroom light, Dipper's chapped lips kissed Mabel's - tiredly, desperately. His hands, now far larger and rougher with his aging, fell into her hips and pushed her, slightly, to the wall. She felt her back press into the framed clown painting her Grunkle Stan stole so long ago, as her own hands, covered in mutli colored band-aids, ran through her brother's brown, curly hair. As their kisses became more heated, his arms wrapped around her tightly, and his stubble began to irritate her chin. But Mabel didn't care. She just needed him. Her hands dropped and began to lift at the edge Dipper's old, worn out t-shirt. But, then, she felt his hands, leaving her long strands, grab her friendship bracelet covered wrists. With his forehead pressed against Mabel's, Dipper had a clear view to look into her brown eyes - the exact color as his - and he could see her, as if in surrender, finally look into his.

"You know we can't keep on doing this." He murmured, his voice still gravelly with sleep, as there passionate frenching had, abruptly, began when both siblings went to the restroom in the middle of the night - too tired to even notice the other heading for the same room.

"Dipper, please. Please. Just one more time."

"That's what we said the last time. And the time before that. And the time before that one."

"And that's what we'll say the next time." Mabel retorted, lifting her lips to grab Dipper's once more, but he moved his head, slightly, to avoid her addictive kiss.

"No. We're not doing this."

The resoluteness in Dipper's voice caused Mabel to, finally, give up, and, defeated, she buried her head in the crook of his neck. Her mouth contorted as she tried to hold back her tears, and she breathed in deeply, trying to remember Dipper's scent: rainwater, fresh air, and moist soil. When Dipper gently lifted Mabel away, he found the tears that she had attempted to keep in were now rolling down her cheeks. His eyes, once exhausted and cold, softened with sympathy. He placed a hand under Mabel's chin, while the other wiped away the tears and, as a finale signature, brushed away her curved bangs.

"It's going to be okay. Especially now that we're at Grunkle Stan's. Here, we can get used to being, you know, split up, in a better...environment. And we have to get used to it, Mabel."

"But what if I can't? What if I never get used to it, and I feel heartache for the rest of my life?"

"Just..try-try and think of how bad it was when we were together. About how annoying it was to keep so many secrets. About the constant stress of being caught. About how we were caught. Do you remember that? When Chelsea found us behind the gym, and now our reputation depends on this stranger? It's too difficult, Mabel. For us to be together, we'd have to give up so many other wonderful things." Dipper said, his voice breaking as he kissed away Mabel's tears. His own eyes were starting to water, as well, which Mabel noticed when his shoulder's shuddered slightly.

"You know, I found someone." He continued.

"What!?" Mabel shrieked, slamming herself into the wall behind her, so as to distance herself as much as possible from her brother.

"Yeah, I did. Her name's Bailey. Bailey Chiffre." Dipper sounded defeated as he admitted this, his head hanging low.

"The redhead Soos hired!?"

"Yeah. I guess I have a thing for redheads." He joked, trying to lighten the mood - but only being met by Mabel's betrayed glare. He tried to explain, "Look, I know it hurts. But, I think, the biggest distraction to all this is by...dating other people. And she's nice. Even you liked her."

"No. I mean, not really. I liked the color of her hair, but not necessarily her."

"Well, you would. I know you would. I'm not saying you two should be friends, but you would like her. She's really loud, and athletic, and...honest."

"She sounds like a bitch."

Dipper rolled his eyes. Despite Mabel's many perfections, she was, undeniably, childish. The main reason their tryst had gone on for so long was because Mabel was too immature to actually think it all through. She just thought about the "now", and never really considered how having an affair with your own fucking brother would actually cause some serious problems in the future. Dipper gave his red eyed, pouting sister, a long, tired stare, as if he were expecting reality to hit her. And when it did, her own expression melted away, and more tears welled up in her eyes. She pushed her lips onto Dipper's, and, this time, Dipper had no intention of stopping her.

Mabel, by pushing on Dipper's shoulder, flipped the two so that Dipper was now pressed against the wall. While his hands roamed down her back, her long, hungry kisses became far more quick and feverish, trailing from his lips, down his jaw, and latching onto his neck - only briefly breaking to pull of his shirt. Abruptly, she gave Dipper one last, desperate hug before dropping to her knees, so that she was now level with his waist. Her heart fluttered slightly when she spotted his dark happy trail, which drifted past the waistband of his basketball shorts, and her lips seemed to rest around that area, causing Dipper's an excitement to form in his gut. But realization hit him, and his eyes fluttered open before, cupping Mabel's face in his hands, he stopped her.

"You don't have to do this. I don't...expect you to do anything you don't like or-"

"I want to." She said, clearly and steadily. Her eyes were looking straight into his, with complete surety.

As if giving permission, Dipper leaned back against the wall, letting out a shaky, breath, and focusing on the locked bathroom door ahead of him. He felt the hot exhale of Mabel's breath as she pulled down on his shorts, letting them drop to his ankles. A tingle ran through him when she grasped his member and put her lips around it, entering him into a sweltering hot heat. His breath hitched as she bobbed up and down, and small, short exhales escaped his parted lips. Even with his eyes closed, Dipper's hands found their way to Mabel's long strands, and they weaved through the smooth hair. He craned his head backwards as he felt a sweet sensation began to rise through him, and Mabel could her a slew of whispered cuss words escape her brother's lips, which slowly got louder as she took him deeper into her mouth, until, with a breathy yell, he exclaimed "Fuck!" While curling inwards. Mabel wiped away whatever fluids had passed her lips, before looking up into her brother's eyes.

He was arched over her, slightly, with his still closed out of ecstasy. His face was red, from blushing, and had a sheen of sweat. With how his thick hair fell around him, the image if a halo formed, and Mabel thought about how angelic her brother could seem. Even when they were doing some of the most sinful things out there. Dipper's eyes slowly opened to find his sister looking back at him with an expression of calm, loving wonderment. His heart seemed to well up with a painful, drowning urge to love, and he abruptly kneeled down to press a kiss into her lips.

This was the last kiss, and the most passionate. Now, both were crying, and their salty tears mixed in with the frenzy, as they both clawed at and kissed and hugged and loved each other. Their seemingly chaotic kissing ended when they just had their arms wrapped around the other, causing a deafening silence to fill the room, and all the two could think about the warmth and the heartbeat of their twin. Slowly, they parted, stood up with intertwined hands, and left the room.

They walked down the cold, dark hallway - numbly, deafly - before entering their bedroom. When they headed off to their two separate beds, the twin's hands, trying to hold onto each other for as long as possible, split apart, finally. The two crawled into bed, facing the wall as they pretended to fall into an unattainable sleep, not daring to even roll over and see the other.

This was it.

This was the last time.