why not guy Share definition Flag A guy who encourages or forces you to do everything that might harm to your "good girl" image. - Oh girl, nowadays I'm dating with a "why not guy" and he always forces me to do the things that I've never done before. why not guy by İnci Asena December 15, 2008 0 0 Get merch Get the why not guy mug. Buy Now — $32.95 See more merch