You can be a big lesbian in Suzy's Strange Saga in some paths.
There are also these:
http://chooseyourstory.com/story/why-i-left-you
http://chooseyourstory.com/story/gay-and-depressed
The title in the last one is a bit misleading, since "gay" typically nowadays refers to a homo dude, but you actually play as a girl in it. (Not really obvious though until it outright mentions it)
Actually now that I'm thinking about it, its not readily apparent that you're female in the first one either. Though the author was female and based it on her real life, so with that being the case, you're a rug muncher in that one too.