Definitely straight in terms of it’s market value, would not sell from promotions related to gay. However, you’d be wise to sneak in subtle outbound to gay content, in the long run that is.
It’s funny how terms, in general, change through the years. Think of the type of common terms your parents used to say when you were young, as well as terms that are far more demographic in usage.
Shemale sells, and was pointed out, a gazillion existing site and reference towards it. We’ve reached that politically correct stage with the niche, which is a good thing because it is becoming more widely accepted, I think there is also a new Television show airing soon featuring transsexuals. But yeah, now be careful which keywords you use for sure, ts, tgirl, transgender, transsexual. Words not to use, she-he, chicks with dicks, tranny, etc.