Tuna Fish Sandwich Share definition Flag (n)The act of rubbing two unwashed vaginas together in a sexual manner. Olga and Bethany were horny even though their water was shut off, so they decided to Tuna Fish Sandwich eachother. Tuna Fish Sandwich by One Twenty7 January 23, 2011 0 0 Get merch Get the Tuna Fish Sandwich mug. Buy Now — $32.95 See more merch