The impact of a parent’s nonmarital sexual relationships on a custody determination depends on the law of the state and the facts of the case. In most states, affairs or nonmarital sexual relations are not supposed to be a factor in deciding custody unless it can be shown that the relationship has harmed the child or is likely to harm the child in the future.

If, for example, one parent has had a discreet affair during the marriage, that normally would not be a significant factor in deciding custody. Similarly, if after the marriage is over, a parent lives with a person to whom he or she is not married, the live-in relationship by itself normally is not a major factor in deciding custody. In the case of live-in relationships, the quality of the relationship between the child and the live-in partner can be an important factor in a custody dispute.

If the parent’s non-marital sexual relationship or relationships have placed the child in embarrassing situations or caused significant stress to the child, then the relationship would be a negative factor against the parent involved in the relationship. In one case, for example, a mother conducted an affair during her marriage with a man who lived in the neighborhood. She and the neighbor periodically were involved in the woman’s bedroom while the husband was out, but the child was home.

This placed the child in a stressful situation–a situation that grew worse when the wife of the neighbor appeared at the door and demanded that the child tell her what the child’s mother and neighbor were dong in the bedroom. The mother lost custody primarily because of her nonmarital relationship and its impact on the child.

Although most states require a specific showing of harm to the child before nonmarital sexual conduct is considered, courts in a few states are more inclined to automatically assume that a parent’s nonmarital sexual relationship is harmful to the child or will be harmful to the child. As with the issue of a preference for mothers or fathers in custody cases, the issue of a parent’s sexual conduct can be one in which individual judges may have personal biases that influence their decisions.