a marin
when you pretend to be a friend in a game like Among Us or Mafia just to stab them in the back later and laugh like a maniac.
I acted like I was their friend in Among Us, then I killed them and laughed like a madman.
In Mafia, I pretended to be a good guy, then I betrayed them and ran off like I was being chased by a bear.
I let them think I was on their side in Among Us, then I killed them and said 'nice try'.