In Finnish we have “kissanristiäiset” (literally means a cat’s christening), which means some trivial and meaningless celebration/event.
In France we’re not here to fuck flies
We don’t mind others’ onions
When someone is about to get late somewhere, we say « Tu vas te faire appeler Arthur » (literally « You’re gonna be called Arthur »)
This expression came during the German occupation, when soldiers would shout « Acht Uhr » (« eight hour ») to people during curfew. It sounds like « Arthur » in French.
Last one. « Faire le Jacques » (« acting like Jack ») means « playing dumb »