Given the no-fault nature of most divorces, the issue of blame related to who caused the end of the marriage does not matter from a legal standpoint. However, during divorce proceedings, if one spouse has been unfaithful during the marriage, this information can affect the settlement outcome under certain conditions.
Extra-marital relationships are potentially relevant, for example, if a valid prenuptial agreement states that divorce settlement consequences will result if such a relationship occurs. However, the distribution of assets between spouses is not usually affected by extra-marital relationship activity, due to the no-fault system available in New York and every other state.
Exceptions can sometimes be made if assets have been directly affected by the extra-marital relationship. For example, if a marital asset, such as the home, is borrowed against by one partner in order to support his or her companion, this could affect how the asset and relevant debt are treated in the divorce settlement.
In addition, if joint funds or marital property were given to a spouse’s companion, these assets could also be affected.
In some states, fault-based divorce is still an option available to spouses. In these situations too, an affair may affect a divorce settlement. In particular, such activity may impact alimony payment obligations.
All money matters aside, extra-marital affairs may affect child custody disputes if, during the course of the affair, the involved parent exposed the children to inappropriate situations or people.
Finally, the emotional response of both spouses to the affair, which may include guilt, anger, resentment, etc., could certainly affect their approaches to the divorce case as a whole. This emotional response is harder to qualify, but is ultimately the most significant consequence for the purpose of proceedings.