Taint is the spot between your ass and whatever genetalia you have. it's the perenium, but it's often called the taint. the reason for that is "t'aint your cooter, t'aint your pooter, that's why we call it taint." or "t'aint your bottom, t'aint your scrotum (scraw-tum), that's why we call it taint."
Bettie: Bob, your mustache is tickling me down there, you know, in my perenium!
Bob: Well, technically it's called the perenium, but I like to call it your "taint".