AU with some angst potential. Dipper manages to control his powers early on, and is able to successfully maintain a human appearance. When he and Mabel go home, it's difficult but they're able to maintain a facade that dipper is toootally human. It requires a lot of deals to keep him physical so much of the time, but they find a way. He still has his demonic moments, but he's able to control it enough or get away from the house to avoid giving himself away. He goes to school with Mabel, and perhaps the two of them keep it up for years even. It gets to the point where Mark and Anna start to suss out that something is off, and tell Dipper that he can tell them whatever is wrong and they will support him. He's really happy to hear this, and is preparing to reveal his secret to them. Then the biggest magic storm since the transcendence happened hits, and Mark and Anna come downstairs one night to see their son, eyes golden, teeth sharp, eating a coyote in the living room, blood everywhere.
