Yes, according to Domestic Relations Law adultery is a valid reason for divorce in New York. However, unmistakable proof of adultery is needed, including witness accounts, images, or reports from private investigators. Adultery-based divorces, in contrast to no-fault divorces, may be challenged, which could raise the cost of the legal proceedings. Unless it causes harm to the family, adultery usually has no bearing on child custody or property partition, while it may have an effect on spousal maintenance.