The phrase casser le cul is long standing French slang, literally crude but commonly used to say someone is being unbearable or breaking your patience. Online, the mémé version spread through French speaking meme soundboards and short video edits, where the joke relies on an older, grandmotherly voice saying something far ruder than expected. Clips like this stay popular because the line is short, recognisable even without context, and flexible enough to answer teasing friends, annoying game moments or frustrating everyday scenes without needing a long setup or explanation.