Unlawfully procuring a marriage license, bigamy, adultery: defense

N.Y. Penal Law § 255.20, under Offenses Affecting the Marital Relationship.

N.Y. Penal Law § 255.20

§ 255.20 Unlawfully procuring a marriage license, bigamy, adultery: 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.