Rumpy pumpy: A day you don’t want to ever happen again?

Buzzfeed UK ask Buzzfeed US what british slang means:

The BuzzFeed UK team sent me (a clueless American) the following British slang terms from across the ocean and I was tasked with guessing their meanings. This is my terrible attempt to decipher British culture.

I have a wonderful idea for a new series of ‘Call My Bluff’…