It's probably fair to say that the majority of human beings are bisexual to some extent. I think what is perhaps more relevant in your case is how monogamous you are. Pretty nearly everyone fantasizes at some point about other partners, if not other activities (kinky stuff, whatever): fantasizing is not 'cheating', nor is having crushes that you know are just crushes and you will never do anything about and/or the object of the crush is entirely unobtainable anyway. Having crushes on women may, for you, be the equivalent of having crushes on slebs: it isn't going to happen but it's enjoyable to fantasize about it.
OK feel free to disregard this bit if you feel it's entirely inappropriate and irrelevant but: some couples find that exploring a little bit on the swinging scene can be an enjoyable way of testing out fantasies and safer than getting mixed up with neighbours/friends/work colleagues because swingers have Rules about good manners and not stalking people and having strings-free fun with goodwill on all sides.