Il pleut

When something is really cool, fun, or awesome.

In French "il pleut" means "it's raining" so if something is dripping in fun or coolness or is so awesome it's raining awesomeness, then "il pleut"

Tyler: dude how about this party
Avery: oh yeah il pleut
Kai: il pleut af

Lucille: did you hear the new Nicki Minaj song?
John: oh yeah! Il pleut!