Semen Fannyjuice Share definition Flag When a guy jerks off on a girls back and the semen runs down the butt crack and spills onto the vagina. I busted a nut on my girls back and semen fannyjuice was everywhere. Semen Fannyjuice by Piss Flaps Monkey October 29, 2010 0 0 Get merch Get the Semen Fannyjuice mug. Buy Now — $32.95 See more merch