A redneck phrase that is used to correct persons who think oral sex is not cheating on a spouse or significant other. Ususally associated with a man performing oral on a woman, but there are other variations that we can all imagine.
Made famous by a call to EITM from Richmond VA. If you dont know what EITM is, then smell my face
Billy Brett: I heard you ate out betty sue last night.
One-armed Jimmy: Hey man, dont say that so loud, Norma Jean is in the next room ...dont you know EATIN IS CHEATIN!