Leviticus 20:19-21

19“Do not have sexual relations with your aunt, whether your mother’s sister or your father’s sister. This would dishonor a close relative. Both parties are guilty and will be punished for their sin.

20“If a man has sex with his uncle’s wife, he has violated his uncle. Both the man and woman will be punished for their sin, and they will die childless.

21“If a man marries his brother’s wife, it is an act of impurity. He has violated his brother, and the guilty couple will remain childless.