Church handbook policy on plural marriage.
"32.6.1.2 Sexual Immorality," General Handbook: Serving in The Church of Jesus Christ of Latter-day Saints, accessed May 17, 2023
32.6.1.2
Sexual Immorality
Incest. A membership council is required for incest as defined in 38.6.10. Withdrawing a person’s Church membership is almost always required.
Child Pornography. A membership council is required if a person is involved in child pornography as outlined in 38.6.6.
Plural Marriage. A membership council is required if a person knowingly enters into a plural marriage. Some plural marriages may occur in secret, with a spouse not knowing about one or more other spouses. Withdrawing a person’s Church membership is required if a person knowingly enters into plural marriage.
Sexual Predatory Behavior. A membership council is required if an adult repeatedly harms people sexually and is a threat to others.