He says he can’t marry me because I was married before.

I am a 34 years divorced mother of three children. Six months ago I began an exclusive fwb situation with a long time (7 yrs) friend who has never been married and has no children. After about 5 months I asked if we could date, he agreed. Within three weeks I discovered that our definitions of dating varied. I had assumed we were in a committed bf/gf relationship, but he insisted that we were just having sex exclusively but still available to talk to other people (as in we were single). The last few weeks we’ve tried ending things and staying friends but we keep sending mixed signals. He was hosting a get together and I decided not to attend the day before which made him upset, he asked for two weeks of no contact, but then changed his mind. He confessed he loves me and my children but that he can’t commit to a relationship because he can’t marry me, and he says he can’t marry me because “I feel like I’d cut myself off if I didn’t get to share two monumental experiences with someone else as a first time.” And “I’d love to be together. The concept seems pointless if its to stay stagnant as just a relationship. Yet the concepts of children and marriage seem like I’d be cheapening the experience, being led instead of exploring concepts together.”

Please tell me what to do! How can I just let this go?