Leviticus 18:20

20 You shall not have sexual relations with your kinsman's wife, and defile yourself with her.

Leviticus 18:20 In-Context

18 And you shall not take a woman as a rival to her sister, uncovering her nakedness while her sister is still alive.
19 You shall not approach a woman to uncover her nakedness while she is in her menstrual uncleanness.
20 You shall not have sexual relations with your kinsman's wife, and defile yourself with her.
21 You shall not give any of your offspring to sacrifice them to Molech, and so profane the name of your God: I am the Lord.
22 You shall not lie with a male as with a woman; it is an abomination.
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.