If you stole a couple of bucks from your daddys wallet and he found out, but instead of punishing you he leaves his wallet out on the coffee table so you don't have to be inconvienced by tiptoeing into his room and taking it off his dresser, pretty soon you'll be taking as much as possible until he said stop. And what if he never says stop?
Unless Daddy finds his balls and says stop pretty soon, Mom will divorce him and he'll lose everything and find himself naked on the street with his dick in his hand...