WHATERYOUDOIN Share definition Flag This is when you run up to someone and hump them while screaming and spitting what are you doing its an mpm thing I ran up to jay and fucked while chanting these words WHATERYOUDOIN WHATERYOUDOIN by Gerry Richardson October 10, 2006 0 0 Get merch Get the WHATERYOUDOIN mug. Buy Now — $32.95 See more merch