let's have some fun 

also know as wanna have fun when two people have some "fun" usually sex or some sort of sexual activity

Boy-Let's have some fun tomorrow

Girl- Anytime

let's have some fun by Chikis777 March 21, 2009

It's a Monday, Let's Have Some Fun 

Easily the stupidest phrase ever used, popularized somewhat by an awkward YouTube video from which plagiarized variation(s) have come. Makes little to no sense, and, in normal conversation, comes across as a huge force

1 - "it's a Monday, let's have some fun"
2 - "I can't believe that kid just said that"

It's a Monday, Let's Have Some Fun by Miiiike Jones September 13, 2012