When someone says this, it’s supposed to be an insult. This insult relates to *ACTUALLY* fucking yourself, and therefor used to call people out for self-cest when in an argument.
Person 1: Go fuck yourself!
Person 2: Fuck me yourself, coward!
Person 1: Ew no you’re ugly.
Hym "Fuck yourself in the face! Classic me. Right up in that face. Heheheheh... Welp... Anyways... Kids are shit. Every time they die an angel gets an erection. If I control those biblically accurate angel drone, my plan to become God worked and I've effectively created a sort of future-self grandfather paradox where I am literally the Christian/Jewish God you worship. I am the flood that consumes the world. I am the fire and the fury that razes Sodom and Gomorrah. If my brain isn't infected and I'm instead becoming an immortal nanobot vampire... Dope. That's dope. We're going to have a lot of fun.... Yeah..."
A colorful method of telling someone to either; a) shut the fuck up b) go the fuck away
c) go annoy the fuck out of someone else
d) an all inclusive phrase of general distaste which includes a-c as well