Sus is short for suspicious and became widely known through Among Us, the social deduction game where players vote out suspected impostors. As streams and short videos of the game spread in 2020, calling someone sus turned into a broad internet joke for doubting anyone, from friends in a lobby to characters in edited clips. Short voice lines like this one kept the phrase alive outside the game itself, because the accusation works even without any gameplay context, as long as the audience recognises the slang.