Leviticus 20:19-21

19You are not to uncover the nakedness of your mother’s sister, or your father’s sister, for the one who does that has made his close relative naked, and will bear his iniquity.

20If a man lies with his aunt, he has uncovered his uncle’s nakedness. They should bear their sin, and die childless.

21If a man takes his brother’s wife, it is an impurity. He has uncovered his brother’s nakedness, and they will be childless.