The phrase kills you cutely comes from online roleplay slang, where actions written between asterisks describe what a character is supposedly doing. Turning that text joke into a spoken clip made it popular in short edits, gaming chats and anime fandom spaces, where cute avatars and chibi characters are paired with over dramatic captions. Its appeal is the mismatch between sweet delivery and violent wording, so it keeps circulating as a reaction sound rather than a line tied to one specific show or game.