Gay male porn turns me on as well. The only rationale I can come up with is this: Porn is much easier to find than erotica. And porn is largely geared towards a male audience. A lot of times I have a hard time buying the woman, as in either she looks too much like a fantasy or I'm not convinced she's turned on and enjoying herself. Lesbian porn is full of make-up and long red nails and high heeled shoes -- all of which a lesbian might be into although I've never met one of them (and as far as all the women I've ever met, no two ultra-femmey women have had interest in each other). So the only porn easy to find, where both partners convincingly portray pleasure, is gay male porn. But, truth be told, any visual image of two people I find to be attractive getting it on and enjoying it turns me on.