Alienation of affection and criminal conversation are potential legal claims or causes of action against a person who committed adultery with your spouse—the paramour or lover with whom your spouse had an affair. These claims are based on the idea that the person with whom your spouse cheated destroyed or alienated the love and affection in your marriage.

Alienation of affection claims are no longer recognized by courts in most states—but Hawaii, Mississippi, New Mexico, North Carolina, South Dakota, and Utah do recognize such claims. And in some states that do or do not not recognize such claims, the cheated-on spouse may seek an unequal division of the marital estate based on fault in the breakup of the marriage.

The details of alienation of affection laws (sometimes called heart-balm laws) vary from state to state among the states that do recognize such claims.

In New Mexico, alienation of affection is a legal claim that can be brought against a third party, typically the paramour, who has engaged in a relationship with someone's spouse, thereby causing loss of affection in the marriage. This type of claim is based on the premise that the third party's actions have interfered with the marital relationship. Although many states have abolished this cause of action, New Mexico is one of the few states that still recognizes it. Additionally, in cases of divorce, New Mexico courts may consider adultery as a factor when deciding on the division of the marital estate. This means that if one spouse can prove the other's fault in the breakdown of the marriage due to an affair, it may lead to an unequal division of assets in favor of the non-adulterous spouse.