Not naive. LOL Believe it or not, erotic gay fiction is a rapidly-growing genre with female authors/readers. 90% of the authors I know who write it, ARE female. Now, if you want to get technical about things... I am omnigendered. Although I'm physically female, my mind is male. The only female thing about me (aside from legal name) is my body. I don't know if I'd ever go through the rigors of transition to male, simply because the surgeries involved are far from perfect, or even desirable, in some cases.
But back to the issue of the genre and its writers... within the female reader/author community, it's generally referred to as 'slash' fiction, the term 'slash' having originated along the lines of the actual mark denoting the pairing (ie. Kirk/Spock; etc...)
While most female-written gay erotic fiction is romantic in nature, that is not always the case. I ghostwrite for three gay porn sites, in which I write "first person accounts" using fake male names. There's no romance involved; just 1000-2000 word sex scenes. LOL