A young man goes to his mother and father to share the news he has found a nice young lady to marry. After revealing who this woman is the father is angry and disapproves. The mother can not see why the boys father is so against it. A few days later the boy asked his father why he disapproves of the marriage. The father tells his son that the girl is his sister but the boys mother does not know. Feeling that he should tell his mother the boys goes and let's her know what the father has said. The mother laughs and said if you want to marry that girl you go right ahead because your father is not your father but he does not know.