The sound grew out of Among Us culture, where players shortened suspicious to sus during emergency meetings to accuse crewmates of being the impostor. As clips of those meetings spread on TikTok, YouTube and Discord in 2020, the word escaped the game and became a general joke for any shady behaviour. Sos Sus riffs on that shorthand by stretching it into a longer callout, similar to an SOS distress signal. Its length makes it popular for edits that build fake tension before revealing something completely harmless or obviously guilty.