Leviticus 18:16 and 20:21 prohibit a man from marrying and having relations with his brother’s wife.
Lev. 18:16 Do not have sexual relations with your brother’s wife; that would dishonor your brother.
Lev. 20:21 If a man marries his brother’s wife, it is an act of impurity; he has dishonored his brother. They will be childless.
Then there’s Deu…