DeMo BoYz Share definition Flag A Demo Boy by definition is a badass who may sometimes act gay and lies about doing drugs and getting girls. Demoz are also extremely strong and enjoy long walks on the beach! :-) Some DeMo BoYz are Justin, Mikey, Mike, Nick, etc.... DeMo BoYz by DEMOBOYZ! April 4, 2010 0 0 Get merch Get the DeMo BoYz mug. Buy Now — $32.95 See more merch