Is it true that all gay men are really bisexual? I mean, look at the guys who have been or are still married to women. Isn't labeling yourself bi or gay a political decision? Anon.
But then look at all the guys -- many more, in fact -- who have never been married to women, and are not in any way, shape or form bisexual. And may not have the slightest sexual or romantic interest in women. Ever.
How you label yourself or identify can be a political decision (or one born of how you see yourself, or want to see yourself and be seen by others). No doubt there are gay men who call themselves bisexual because they feel it makes them -- somehow -- more masculine. [In gay society, a man can have sex exclusively with men and still be considered something of a stud. Outside gay society, a man is seen as a "stud" only if he has sex with women. Some guys need to seen as studs by the entire world, and especially by their straight friends and family.] I don't know if a man who identifies as gay would label himself bi for political reasons, unless it's to show solidarity with a bi male partner.
I believe there are men who see themselves as bisexual but who label themselves gay for political reasons. [But many, many more men who label themselves gay simply because they're gay.] They may do this to show solidarity with other "queer" Men Who Love Men, or because of their recognition that if they experience persecution it will more likely be due to their same-sex attraction and relationships than to whatever attraction or relationships they may have with the opposite sex.
A genuine bisexual has much more than a passing interest in the opposite sex, and their relationships with women are not for appearance's or career's sake, or due to internalized homophobia or self-denial. Some gay men may have a mild or occasional interest in, or sexual experience, with women, but their attraction to and interest in men is far more overwhelming. Although some men in this position, as well as others, may choose to call themselves bisexual, their overwhelming interest in men (even if they're married to women) in my educated opinion, makes them gay, not bi.
Married homosexual men (as opposed to married bisexual men) are technically bisexual because they do sleep with women and have biological children. However, before one talks about bisexuality one has to consider this: I've met, befriended and interviewed literally hundreds of men who were once, or still are, married to women, and the vast majority of them say they are gay, not bisexual. Many, perhaps most, of them, say that sex with their wives was unsatisfying (as opposed to sex with men), and that they had to fantasize about males during the sex act. In some cases they would not have been able to achieve erection let alone successful penetration, without the homoerotic fantasies. Not just with their wives, but with virtually any woman. That doesn't sound bi to me -- it sounds gay.
So, no, it's not true that all gay men are really bisexual. Saying so is tantamount to saying that all gay men can change over to straight, change their orientation, when that flies in the face of all evidence to the contrary, "sexual fluidity" be damned. A gay man can sleep with a woman, father children, but that doesn't make him straight or bi. In fact, one of the biggest mistakes many bi-identified individuals make is to automatically assume a Man Who Loves Men is bisexual just because he is or was once married to a woman.
Funny, nobody ever seems to think that all straight men are really bisexual. Wonder why?