Christa's reactions when discussing her scars (from a werewolf):
Adam: Seriously, Christa, we both know how you got that scar on your arm. Matt: And the rest. [holding his hand to his chest, showing where they are]
(Adam and Christa both look at Matt) Christa: What? (looking shocked) Matt: Nothing. Christa: When did you see? When did you see? Adam: See what? Christa: I think I know exactly what he was doing that day, don't I, Matt?
It turns out Matt was spying on her in the locker room.
When looking for Matt's body, Christa transforms:
Adam: Unless it WAS in there. Werewolves'll eat anything. Matt: I wanted to get inside you, but not like that!
(Matt fist bumps with Adam, while Christa vomits)
When Matt comments that if Christa was to jerk them off, given how he and Adam are invisible on camera, she'd look like she was ski-ing.