I've been dabbling with Gravity Falls shabiki fics of late, and I may have a new one for wewe guys concerning Robbie Valentino.
I think Robbie is adopted, and here's why.
Think back to the episode "Love God" when Mabel is walking down the hall to Robbie's Room and passes the portraits on the wall.
(1) Young Robbie, Happy, Gleeful. one of the first pictures, before he found out he was adopted.
(2) Robbie, about Dipper and Mabel's age, still happy, but slightly distant. Robbie was a smart kid, just like Dipper and Mabel, with natural musical talent, Julliard level talent, and it's about this time he found...

Into the Dare Contest between Dipper and Stan Pines, the latter dares Dipper to skateboard to Greasy's diner and back to the Mystery Shack, completely naked. "How naked?" Dipper asked Stan. He replied fourth base, meaning "no hat, no shoes, no socks, nada". "What about the ladies?" asked a concerned Dipper. Stan threatens to declare Dipper a "chicken for life". He also points out that Dipper will wake up to "Good Morning, Chicken", and he would also cluck "Here Comes the Bride", while holding up his middle finger, when Dipper gets married. However, not wanting to be threatened, Dipper throws...