Slut Stack Share definition Flag When you stack two or more sluts vertically and then alternate from one hole to the next, moving up and down the stack. "Hey man, I hear Jessica and Ashley got slut stacked last night at the kegger." Slut Stack by J-Rip September 12, 2009 0 0 Get merch Get the Slut Stack mug. Buy Now — $32.95 See more merch