flop jacket Share definition Flag a condom, but only applies to a flacid penis. If erect, it becomes a skin suede shoe. Yeah, I had the trojan on, but her dank was quite stank so it just became a flop jacket. flop jacket by MrCerebellum August 19, 2008 0 0 Get merch Get the flop jacket mug. Buy Now — $32.95 See more merch