Dipper takes Bill to a rock concert to show how wild humans can be. Dipper is 16 Bill is an old demon.
Mystery shack
"A rock concert?" Bill asked dumbly "Humans have concerts just for rocks?" He said making Mabel laugh.
"Ha! Good one Bill!" Mabel chuckled then noticed Bill's serious face and stopped "Wait you weren't kidding?" She asked.
"Nope." Bill shook his head and at that time Dipper comes in wearing a ripped black shirt showing off her stomach with a red vest, black leather pants, black boots with pink hearts, hair hang loose with pink highlights, red lipstick and purple eye-shadow found her eyes.
"What do you think?" Dipper asked sticking out her tongue and did the devil horns.
"You look devilishly delicious." Bill purred wrapping his arms around Dipper who puts her arms his neck.
"Well to answer Bill's question." Mabel interrupted the couples moment "A rock concert is where people go to to listen to hardcore music from the 1960s." She said then winked.
"And my little Pinetree is okay listening to hardcore music?" Bill asked eyebrow raised.
"Earlier today you said humans can't be wild like demons so I thought we'd do something wild!" Dipper said kissing Bill's cheek leaving a smooch mark.
"Okay then let's go!" Mabel shouted in a pink skirt and black sweater saying 'rocklicious!' With lots of sparkles.
At the concert
"This is really loud!" Bill shouted wearing pink pants, black boots, no shirt but a black vest, and his wild blond hair has red streaks.
"I totally agree!" Dipper shouted back both in an open field Rocking out to the band.
"Hey wanna dance?" A man asked his hand out to Bill who shook his head.
"Can't I'm here with my girlfriend!" Bill shouted arms around Dipper who kissed him on the lips making the man frown and walk away.
"I'm gonna crowd serf!" Dipper yells wildly making many people grab her using their hands serf her to the stage.
"Hey Pinetree wait for me!" Bill shouted doing a crowd serf after his girlfriend she apparently goes wild at concerts for some reason.