New York Penal Law Section 255.20 - Unlawfully procuring a marriage license, bigamy, adultery: defense.

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.

Last modified: February 3, 2019