I Love My Room Mate

I'm in love with my roommate. I am in a committed relationship, but I love my other male room mate and have for years. That wasn't really an issue until I found out that he may also have feelings for me in return. But I'm unsure because he didn't out right say it.
I love my fiance. Our sex life is great and so is our romantic life. I don't understand why I can't get my roommate out of my mind. He knows about my feelings regarding the room mate, but I said I moved on a long time ago. He is still worried I'm gonna leave him or cheat on him, and that makes me sad.

I don't know what to do. I don't know if there is anything there with my roommate or what. I'm with a great guy, but being on the verge of marrying him while having been in love with my roommate for longer than I've known my fiance seems problematic. My roommate and fiance are my best friends. I'm so scared of fucking everything up. But I'm even more scared of making the wrong choice. Any advice?