The phrase translates from French as asking who is in your room, and it circulates online as a short prank and reaction clip rather than as a line tied to a documented film, show, or song. Its appeal comes from the everyday situation it names: hearing an unexpected sound at home and confronting the possible intruder, guest, or hidden friend. Because the clip is only a few seconds long, it fits easily into short video edits, messaging jokes, and prank videos, where the question creates suspense before the reveal. That simple, relatable setup helps explain why it keeps being shared.