Commonly misinterpreted as a spelling mistake of the word "Beautiful", this completely intentional play on words, does in fact describe the act of sex with a beautiful woman.
This originated in Bolton, UK. Where sex with a girl who is considered 7/10 or above is a complete rarity, hence the need for a word to describe this incredibly scarce moment.
It can only be likened to seeing a live pangolin in the wild.
"Jack, what did you get up to after the club?"
"I copped a Beautifuk"
*celebrations commence*