After a six-year marriage, a mother and father divorced in January 1993. The trial court awarded custody of the daughter to the mother. Afterwards, the mother began a same-sex relationship with another woman, G. S. The mother and G. S. lived in a three-bedroom apartment together with the mother’s daughter. The mother and father had an agreement that the mother and G. S. would keep their relationship discreet, meaning that they would not share a bedroom or show affection towards each other in front of the daughter. After the father remarried, he discovered that the mother and G. S. shared a bedroom, kissed in front of the daughter, and allowed the daughter to sleep with them in their bed. The father moved to have the divorce judgment modified to obtain custody of his daughter. The mother’s evidence included testimony from various experts that the mother’s homosexual relationship was beneficial to the daughter and that there was no significant difference in children who were raised by homosexual couples. The father introduced evidence from a pastoral counselor who suspected the daughter may have been sexually abused. The trial court granted custody to the father, finding that the change would materially promote the daughter’s best interests. The Court of Civil Appeals reversed, finding that evidence of a parent’s homosexuality could not support a change in custody unless the trial court found that the misconduct had a substantial detrimental effect on the child and that there was no evidence in this case that the mother’s relationship had a substantial detrimental effect on the daughter. The father appealed.