Is my boyfriend married?

[DevilBoi]

I'm a 24y/o guy, I have been dating my boyfriend for five years and we've been living together for over four years. He's 45 and he came out at a late age, we get along great and he knows everything about me but I don't know much about his past. I know he had a girlfriend for five years before he came out and that he got her pregnant once but she miscarried, it never bothered me until his mother said "Oh, his wife stopped by to visit me yesterday". I asked him about it and he said he was never married, but a few months before that my best friend was house sitting for us while we were away and his mother introduced a woman that was visiting her as my boyfriends wife to my friend. Last night we were watching show on TV about gay people that used to be married and he said "I remember when I got engaged" so I asked him to tell me how did he do it to which he replied that he doesn't remember. How do you not remember one of the most life changing events in a persons life? He said he remembers getting the ring so I asked him what made him get it. He got really defensive, flipped out on me and left the house. What bothers me about it is that he promised a woman to spend the rest of his life with her which i bet was one of the happiest moments in her life and then just dumped her? I know it's silly but I can't get over the idea that they're still married or might be divorced, hell, for all I know he might have some kids out there. It really bothers me, but he refuses to talk about it with me and calls me annoying. I just want to know more about his past but find it suspicious that he gets so defensive over it and his mother still calls the woman his wife. Why would she do that if they were never married? Sorry for the long post, just needed to get it out of my system and see your take on it. Also, we played with the idea of getting married but he keeps coming up with excuses not to do it.