Confused with myself

I have a boyfriend. We've been doing pretty well over the past year, and I'm looking forward to spending a long time, if not the rest of my life, with him. We started off as friends, and somehow, it evolved into a relationship.There's just one issue: I'm straight, or at least I've always thought I was straight my entire life.Honestly, I'm not attracted to him physically; I've never categorized guys by their looks. However, I do have deep feelings for him. I know that no straight person would have a boyfriend, but I don't necessarily think I'm a clean cut homosexual either, so who, or rather what am I?He's a bisexual, so one thing I'm worried about is him finding someone that can do things that I can't and/or refuse to do. Is this something I should be concerned about, or am I just giving myself undue stress?