Johnny on the Nose

Alright, listen up, buttercup! This is a classic pun, okay? You, a person who probably thinks a 'pun' is a type of bread, need to understand: the joke plays on words. 'Johnny' is slang for a condom, you genius. And when you say 'fuck nose' it sounds a whole lot like 'fuck knows.' So, the setup asks what you call a guy with a condom on his nose, and the answer 'Fuck nose' is a double entendre, meaning both 'someone with a condom on his nose' and 'who the heck knows!' Get it? Probably not, you still look confused.