N.Y. Dom. Rel. Law § 248

§ 248. Modification of judgment or order in action for divorce or\nannulment. Where an action for divorce or for annulment or for a\ndeclaration of the nullity of a void marriage is brought by a husband or\nwife, and a final judgment of divorce or a final judgment annulling the\nmarriage or declaring its nullity has been rendered, the court, by order\nupon the application of the husband on notice, and on proof of the\nmarriage of the wife after such final judgment, must modify such final\njudgment and any orders made with respect thereto by annulling the\nprovisions of such final judgment or orders, or of both, directing\npayments of money for the support of the wife. The court in its\ndiscretion upon application of the husband on notice, upon proof that\nthe wife is habitually living with another man and holding herself out\nas his wife, although not married to such man, may modify such final\njudgment and any orders made with respect thereto by annulling the\nprovisions of such final judgment or orders or of both, directing\npayment of money for the support of such wife.\n