This French phrase, literally meaning in underwear and socks, has become a shorthand online for being caught unprepared or dressed down at home. The clip is shared mainly as a reaction sound in memes, short videos and chat messages, where the humour comes from the vivid, slightly embarrassing image it creates in just three words. Because the phrase is short, clear and easy to recognise even for non-French speakers, creators reuse it to punctuate lazy mornings, outfit fails and awkward at-home moments. Its appeal lies in that simple, relatable picture rather than any single viral video.