Mush Tush Share definition Flag The loosening of the anus after a girl has copious amounts of anal sex. I went home with that skank from the club and when I stuck it in her ass, I found out she had a total mush tush! Mush Tush by MistahBradshaw August 30, 2010 0 0 Get merch Get the Mush Tush mug. Buy Now — $32.95 See more merch