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.
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