I think your experience is pretty common among women. If you're genuinely interested in the answers to some of those questions, I'm reading
this book in my Sexual Diversity class right now and it has a lot of interesting information about women's sexuality and its inherent fluidity. The author, a feminist psychologist, conducted a long term empirical study of a group of women showing that the rigid categories of sexuality (straight, gay, bi, asexual) don't really work for women -- women who identify as straight often have experiences with other women, women who identify as lesbian or may guys, women who identify as bisexual may only ever date or sleep with one gender, and so on. The reasons for this are numerous, and are not exclusive to women (men are prone to fluidity as well, though to a lesser degree), but fluidity is far more common for us than certainty or rigidity.
I think that's part of it, but not necessarily because women have a broader idea of what is
physically attractive. I think we are more likely than men to develop an attraction based on an emotional bond. Which is, of course, not to suggest that all women who engage in same-sex activities do so because of a deep emotional attachment (lord knows I haven't), but because it's not uncommon for women to development an attraction or a sexual relationship with someone other than what they're typically attracted to just because of an emotional connection. In my experience, a straight man can develop a very strong emotional bond with a male friend, but it is not as likely to develop into a sexual attraction or curiosity as it would in a situation with two women.
I think it also has a lot to do with what our society finds to be acceptable behavior -- women can recover from a little experimentation without a huge blow to their reputation, but men really can't.
Especially since it's always discussed in terms of a "versus." It's always oppositional. As if such a complex thing as one's sexuality could only be caused by genetics OR environment.
I can't think of any way they wouldn't both be involved. Genetics and biology may be involved in determining one's potential or predisposition towards same-sex attractions, but there are countless outside factors -- family, religion, culture, etc. -- that are involved in determining whether or not that potential will ever be expressed, or even recognized. I've always been happy enough with men that I often wonder how different my sexuality would be if I grew up in a more conservative environment than I did. Even amongst the straight members of my family, ness is pretty damned common. If that hadn't been the case, if I didn't grow up open to the possibility, I'm not sure that I ever would have noticed my attraction to women. I don't know that I would have even recognized something was missing.
There's no one right way to be gay or bisexual by which everything is measured. Just as there's no one way to be straight.
I don't doubt the possibility that celebrities who express their fluidity may be doing so for publicity, but neither do I assume it.
There's a school of thought amongst feminist theoreticians that male phobia is rooted in the hatred of the feminine. This doesn't mean the hatred of women, of course, but rather the devaluing of traditionally feminine characteristics. For a man to be intimate with another man, he is willingly adopting "feminine" characteristics, which is hugely threatening. This is why the quickest way to insult a man is to call him a pussy, or a , or a , or to otherwise question his masculinity.
It is not just participating in this behavior that is socially questionable, though. Even the tolerance of male sexuality can be a threat to one's masculinity, as part of the male performance is the explicit rejection of those feminine characteristics.
Liking/accepting two women together doesn't threaten one's masculinity. In fact, it reinforces it. Tolerating the idea of two men together, however, directly calls into question one's masculinity. Therefore, it is potentially far more damaging to be okay with the idea of two men having sex than it is to be okay with two women having sex