When you don't want others in a public restroom to hear your explosive diarrhea. You pucker up and you flush the toilet at the same time while you dump everything you've got. The toilet flush tries to cover your ass blast noise. Also gets rid of some lingering diarrhea smells.
Girl 1: Honey, I had to dump so bad but the bathroom was full and I didn't want to be embarrassed so I had to pull a Flash Flood Dump.

Girl 2: Dang I know what you mean hun, last time I did that the toilet cut off before I could stop. It was embarrassing. :/
by The Manchester Molester December 6, 2014
Get the Flash Flood Dump mug.