wtfmfwtfayt Share definition Flag What the fuck, motherfucker, what the fuck are you thinking?; taken from a song of same title by Jim's Big Ego You ate some anthrax for breakfast? WTFMFWTFAYT?! wtfmfwtfayt by Aaron MacKenzie December 13, 2005 0 0 Get merch Get the wtfmfwtfayt mug. Buy Now — $32.95 See more merch