back-door-gasm Share definition Flag A back-door-gasm is the cumgasm a guy has when he seeds another dude in his asshole. Matt has at least two back-door-gasms in me tous les jours! back-door-gasm by eda-skip November 1, 2021 0 0 Get merch Get the back-door-gasm mug. Buy Now — $32.95 See more merch