Under NH law an innocent party may request a divorce decree based on the fault of another party for certain enumerated causes. If a fault based divorce is granted it can result in a distribution of assets that favors the innocent spouse. The most common cause of a fault divorce is adultery that is defined as voluntary sexual intercourse between a married person and some other person who is not his spouse.
In the case of In The Matter Of Danielle Ross and Christopher Ross, the New Hampshire Supreme Court had an opportunity to discuss the defense of recrimination. In that case Mrs. Ross filed for divorce and her then husband Mr. Ross filed a cross-petition alleging fault based on her adultery. However, eleven months after the couple separated, but before the divorce was heard, Mr. Ross began a sexual relationship with another woman who was not his wife. This was grounds to dismiss his cross-petition for a divorce based on fault. The Court explained that he was no longer an “innocent party” as he too was committing adultery. The Court wrote that even though the adultery of Mr. Ross did not cause the breakdown of the marriage (a requirement for a fault based divorce), it effectively barred him from alleging fault based on his wife’s prior adultery. The Court invited the Legislature to change the law if it feels that this result is unfair.
The point is that if you catch your spouse being unfaithful you should wait until your divorce is final before beginning a sexual relationship with another person.