When you go to the beach and get sand in your vagina. Then you have sex. The resulting splooge - sand mixture is referred to as sand gravy.
Man, I wish we'd played volleyball in the gym instead of at the beach, because this sand gravy really chafes.
by Vashmil March 21, 2015
My dog is so stupid, he drank too much sea water and shit sand gravy all over the back of my car on the way home.
by Vashmil March 27, 2015