I DON'T OWN GRAVITY FALLS

At Candy's house, there is a massive party. A large group of people are on the dance floor, and the rest are littered around the walls talking, a few enacting PDA. Dipper and Pacifica  are standing by the stairs with Grenda, Candy and Drew.

"I think it's weird that Mabel didn't tell me about her boyfriend."

"Yeah Dipper, it is. Like, me and her went to the mall every Saturday for 3 weeks to find someone, and the fact she didn't tell me when she did, it's just weird?"

Candy looks over. "I think it's kinda romantic, like a secret romance. She didn't want to show anyone until the party. By the way, where is she, didn't she come with you?"

"No, she was still getting ready, said something about putting on her favourite necklace or something."

Grenda looks over to the door. "Isn't that her there with that guy?"

They all look over to the door and see Mabel walk in Bill Cipher in his human form, holding the door open for her. They both walk over to the group. "Hey guys, how are you?"

Pacifica looks at Bill, and then at Mabel, and then at Bill, and then at Mabel again. "Hey Mabel. Who's this?"

"Oh, of course. Guys, this is William, my boyfriend."

Does the quirky half wave half salute. "Sup, call me Bill."

Dipper looks at Bill. "Hey Bill. I like your suit, very sharp. What's with the eye-patch?"

"Oh, it's because of an accident I had when I was younger with a high bed and a thin metal pole."

The whole group apart from Mabel cringe. "I prefer to wear the eye-patch over the eye plaster because it looks so much cooler. Plus, if I ever got to a pirate party," taps the eye-patch with his forefinger, "got it covered."

Everyone laughs. Mabel chuckles. Bill looks at her and smiles. Dipper turns to the snack table and grabs a drink. "Anyone want a drink? Bill?"

Bill waves his hand and shakes his head. "No thank you, I'm not thirsty."

"Ok, anyone else?"

Everyone else nods and receives their drinks. Suddenly, the music changes, and everyone piles on the dance floor.  Bill turns to Mabel. "Come on, let's dance."

"But you can't touch me?"

"Hasn't stopped us yet." He smiles.

He leads Mabel to the middle of the dance floor, where he started to dance. Mabel sighed and shrugged and started to dance along with him, moving her body in time with his. He starts to make stupid faces and Mabel starts to laugh. Bill's smile looks so big it's at risk of flying off his face. Pacifica and Dipper are dancing near by. Pacifica looks at Dipper. "I think he's nice."

"Yeah, he seems to make Mabel happy."

When the song ends, Mabel and Bill walk off the dance floor. Mabel sits on the stairs and rubs her forehead. Bill sits next to her. "What's wrong Mabel?"

"I'm just really hot."

Bill smirks. "Yeah you are."

Mabel shoots him a look. Bill chuckles. "Sorry, but you set yourself up for that. I'll get you a drink."

Bill walks over to the snack table and is about to grab a drink, when Dipper grabs it. "Don't worry bro, I got you."

Dipper takes the drink to Mabel, followed by Bill. Mabel takes her drink and Dipper turns to Bill. "Thanks for looking out for my sister Bill, I appreciate it." Dipper holds out his hand for Bill to shake it.

"She's my girlfriend Dipper, i care about her." Bill goes to shake Dippers hand, but Mabel calls for him. "Sorry Dipper, I have to go see what Mabel wants."

Bill walks over to Mabel who takes him upstairs. "What's up?"

"What are you doing?"

"Talking to Dipper?"

"You can't shake his hand, you can't touch him. He'll work out who you are."

"Yeah, I forgot. You still don't trust me."

"That's not it Bill. I trust you, and the way you've been acting this evening, well I hate to say it, but I might even be falling for you."

Bill's eyes light up.

"The party is almost over. You can touch me."

Mabel's necklace lights up for a second before going back to normal. Bill grabs Mabel's hand and leads her back down to the dance floor, where everyone was slow dancing to the last song of the night. Bill holds his hands on Mabel's waist and pulls her in close, swaying along with the music. Mabel rests her head on Bills shoulder, and melts into his figure. When the song ends, Bill spins Mabel out and pulls her back in, into for his well placed lips to push their way into Mabel's. He pulls back and sees Mabel look shocked, before she pulls him back in for another hug.

The party ends and Mabel, Bill, Dipper and Pacifica start to walk home. They reach the house, and Pacifica walks in with Dipper as she is staying over. Mabel and Bill wait by the door. "So Bill, what happens now?"

"You take off the necklace, and I return to the dreamscape. If you want me back, just put the necklace back on. I had fun tonight, I'm glad you decided to trust me."

"Hey Bill, I know we said dating for the party, but I feel like I can't just have that. I want to be dating for real. And I may take off the necklace now, but it's going back on as soon as I wake up." Mabel kisses Bill on the cheek. "Goodnight William."

"Goodnight Mabel."

Mabel closes her eyes and takes off her necklace, and as quickly as she could open her eyes again, she was standing on her own. She sighed and looked at the sky. "Goodnight boyfriend."