That female sexuality is more malleable than male sexuality is, that women are more likely to ‘experiment’ with same-sex intimacy (the majority of whom still identify as heterosexual after having done so) than men are, and that men who self-identify as bisexual tend to really just be homosexuals who don’t want to come all the way out of the closet are all ideas I’m familiar with and assume to be generally correct.
The GSS, which began explicitly asking about sexual orientation in 2008, provides some relevant data.
That data appears to prove Milo correct. While 65.6% of self-identified gay men say they have never had a female sexual partner, only 33.9% of lesbians say they have never had a male sexual partner.
Additionally, women are twice as likely to identify as bisexual as men are while also being about one-third less likely to identify as lesbian as men are to identify as gay (rather than bisexual). If non-heterosexual men and women were, in practice, exclusively homosexual and bisexual at equal rates, we’d expect the fact that women are more likely to identify as bisexual and men more likely to identify as gay to mean that, among those women who did identify as lesbian, exclusive homosexuality would be even more pronounced than it is among gay men. That, however, is not the case.
At a minimum, gay men are twice as likely to be exclusively gay as gay women are, and the true multiple is probably even higher than that.
Milo knows his his stuff, gay and otherwise (or most of it, anyway).
GSS variables used: SEX, SEXORNT, NUMWOMEN(0-989), NUMMEN(0-989)