backwash baby Share definition Flag A baby resulting from cum leaking out of a girl's ass and into her pussy after anal sex. It doesn't matter if he fucks me up in the ass, I'm gonna let it all run out and make me a backwash baby backwash baby by Dr MDrr November 30, 2016 0 0 Get merch Get the backwash baby mug. Buy Now — $32.95 See more merch