Sometimes, Waddles had nightmares. He'd squeal, and kick, and sometimes steal Mabel's blanket from her in the middle of the night. (She'd have to steal it back.)
But she was used to it. Gravity Falls was weird, so she understood the pig's fears and coldness. She could protect him.
Her brother was a different story.
Because she'd been so stupid to fall for some puppet-kissing freak, her ignorance toward her brother almost cost them his life. Needless to say, after being possessed by a triangle demon that invaded his body and mind, he was paranoid.
Now, Dipper Pines couldn't sleep. He tossed and turned, chewed on his shirt a bit, and eventually got out of bed and went to the bathroom. Maybe Bill's still in his head. Maybe he's still controlling him. Maybe he's not safe. Maybe... he'll never be safe.