HBFM Share definition Flag Stands for Holy Butt Fucking Moses. An exclamation to be saved for only the most intense of situations. HBFM!! My whole family just got killed by zombies!!! HBFM by ptwnstargazerrr July 10, 2011 0 0 Get merch Get the HBFM mug. Buy Now — $32.95 See more merch
