I might be late to the party here, but I just wanted to chime in that my former husband and I went through this. He (now she) came out as MtF. I am not straight (bi), but I married them in part because I was attracted to their masculinity, which was now going away. I no longer found myself physically attracted to them. We went to marriage counseling, but ultimately decided to divorce. It was very hard, but it was ultimately for the best, for both of us. We remain friends and talk almost every day and it's been 7 years since the divorce.
If you truly love someone, you set them free.
Call yourself whatever you're comfortable with. I'm a woman and I call myself bi, but I've been with a man for 5 years, yet I still sometimes see/interact with women and I find them so attractive that I blush and get nervous around them. Yes, I am with a man, and I find men attractive, but I find women equally attractive. Just because I am with a man now, doesn't make those feelings for women go away, ever. Should I NOT call myself bi because I'm with a man? No, the attraction to women is always there, regardless.