Tenue de soirée is a 1986 French film directed by Bertrand Blier, known for its dark comedy and sharp, quotable dialogue. The line 'c'est pas forcément grave' translates as 'it's not necessarily serious,' and its appeal comes from that deliberately low-key French understatement. As a short soundboard clip, it circulates mainly among French-speaking meme creators and fans of the film, who reuse it to deflate awkward or unlucky moments. Its brevity and calm delivery keep it easy to drop into short videos, where the humour lies in refusing to overreact.