Sus comes from Among Us, the social deduction game released by Innersloth in 2018 that surged in popularity in 2020. Players shortened suspicious to sus when accusing crewmates of secretly being the impostor, and the word quickly spread to TikTok, Discord and gaming streams as a general accusation. Clips that read the phrase aloud literally became a small reaction format, used whenever on-screen text or a chat message calls someone out and the audio underlines the joke for viewers who missed it.