mustard buster Share definition Flag Mustard Busting is the act of jerking off with mustard smeared over ones cock “My Cock is yellow and tingly, i must be a mustard buster.. actually ima go home and mustard bust right now!!” -Gage Gus mustard buster by mattnotgus September 24, 2019 0 0 Get merch Get the mustard buster mug. Buy Now — $32.95 See more merch