Side Undy Dog Share definition Flag Performing doggy style without removing the woman's underwear; instead, slightly parting them to the side. "Bitch was too lazy to take her undies off so I gave her the Side Undy Dog" Side Undy Dog by Semicolon Leftbracket September 28, 2009 0 0 Get merch Get the Side Undy Dog mug. Buy Now — $32.95 See more merch