I'm not arguing that a relationship in which one person is purely into it for non-sexual reasons, but is also sexually attracted to the other gender, is a good one.
I'm simply arguing that sexual orientation is not all about sexual attraction and urges. People have urges for companionship, for love and affection, as well. One's orientation is a factor of all of these things, and they can be present in varying degrees. The "ideal" relationship would, of course, involve all of them, but I don't see the sexual component as the one which should define you completely. If you have romantic feelings towards women, and a sexual attraction towards men, then I guess I might see that as some form of bisexuality, because the sexual aspect is there with men and the emotional/romantic aspect is there with women – and while ideally both would be present, that's not necessarily the case, and I don't think the absence of one is a make or break-type thing.