jelly thumping Share definition Flag action: a game girls play at parties where they try to fuck as many fat guys as they can before the end of the night. me and veronica were at that party last night, and she won our game of jelly thumping. jelly thumping by amandaxbandana October 15, 2007 0 0 Get merch Get the jelly thumping mug. Buy Now — $32.95 See more merch