New York Laws
Article 255 - Offenses Affecting the Marital Relationship
255.20 - Unlawfully Procuring a Marriage License, Bigamy, Adultery: Defense.


defense.

In any prosecution for unlawfully procuring a marriage license,
bigamy, or adultery, it is an affirmative defense that the defendant
acted under a reasonable belief that both he and the other person to the
marriage or prospective marriage or to the sexual intercourse, as the
case may be, were unmarried.