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 Hampshire, the claims of alienation of affection and criminal conversation are not recognized by the courts. New Hampshire does not allow for lawsuits against a third party (the 'paramour' or lover) for the breakdown of a marriage. This means that a spouse cannot legally sue the person with whom their spouse had an affair for alienation of affection or for disrupting the marital relationship. While some states do recognize these types of claims, New Hampshire is not one of them. However, when it comes to the division of marital property in a divorce, New Hampshire courts may consider the fault of the parties, including adultery, when making an equitable distribution of assets. This means that while a direct legal claim against a third party for alienation of affection is not possible, the actions leading to the breakdown of the marriage, such as adultery, can potentially affect the division of marital property.