The phrase comes from gaming culture, where friendly fire refers to damage dealt to teammates rather than opponents, and many games warn players against it during matches. Online, the line has been lifted out of that context and reused as a reaction sound for any moment of accidental or intentional betrayal, from multiplayer fails to real-life pranks. Its popularity endures because the wording is clear, quotable, and instantly understood even without gameplay knowledge, making it an easy drop-in punchline for short-form videos and streams.