Green’s Dictionary of Slang

to be the active partner in an act of fellatio.

1974		(con. 1945) E. Thompson Tattoo (1977) 493: He began to really fuck her face, not caring a damn for her.
1990		S. Morgan Homeboy 277: Billy [...] slammed her up against the cage’s wire mesh, which he clutched to facefuck her for all he was worth.
2002		an1662 ‘First Time’ on Nifty Erotic Stories Archive 🌐 I nearly dropped to my knees, the person on the bed getting face fucked was my butch big jock brother.
2005		E. White My Lives 234: One day T burst into the filthy, shit-streaked [...] toilet and started fucking Teach’s face.