Engagement gone wrong? Here’s what you need to know… In New York, an engagement ring is considered a “conditional gift” meaning that if the marriage does not take place, the individual who proposed may ask for the ring back. However, If the ring-giver was still married when he or she proposed, the ring is no longer a conditional gift -- it's just a regular gift. And those don't have to be returned.
(New York Civil Rights Law Section 80-b5.)