The phrase plays on sus, short for suspicious, the slang popularised by the social deduction game Among Us, where players accuse each other of being the impostor. The joke works because thank you sounds polite while sus turns it into a playful accusation, a contrast that fits gaming clips, streams and short videos. It spread through Among Us memes and edits, where creators use it to call out friends, highlight betrayals and react to unlikely excuses. Its simple wording keeps it easy to reuse in new contexts.