I have been dating a military man for over a year and we WERE engaged to be married. I found out a day ago that he is still legally married to his wife of 14 years. He tells me that he and his wife are estranged and he has no idea where she is. He further tells me that they never lived together and were separated in a matter of months. Does the separation matter since they are still legally married? Is she eligible to receive his benefits? Or will he be responsible for taking care of her?

If they are married then she is entitled to what is legally hers. That may be pensions and/or even spousal support. In some states a 14 year relationship can have spousal support lasting a lifetime.