I'm new here, both to this particular thread and to the Paizo forums in general. I'm jumping in because I'm so darn EXCITED to see this post here.
I'm bisexual, though most of my players and family aren't aware of it. Being married and monogamous, it largely doesn't come into conversation much, so I let sleeping dogs lie.
Except when it comes to games. I both play and GM (Pathfinder rules, mostly homebrew setting) and for my character building, I use utterly elaborate sexual orientation and gender identification charts to define the sexuality and gender of my characters and NPCs. I've broken it down by cultural area and race, too. I've spent what some people might call an abnormal amount of time thinking about how my characters relate to sex and gender.
For an upcoming game I'm GMing, I've already asked my players to define their character's sexuality on the Kinsey scale (or to include a complete backstory explaining their asexuality, if they choose). Part of it is because my brother-in-law is playing a female socially-licensed prostitute and I want all the players and characters to have decided beforehand how they might feel about being in close quarters with her for long periods of time.
I'm including elements of orientation and gender identity in a game for teens I run with our local library, too. The kids don't know this because they haven't talked with her extensively, but I have a transgendered cleric in town; she was born male but when she answered her god's call, she was granted a body which reflects her identity. It's caused her to be a little neurotic about adhering to her clerical calling for fear the god will take back the blessing if she proves a disappointment.
Something I read on Tumblr a while back really emphasizes how I feel about gender identity and sexuality inclusion in fantasy games: it's hard to escape onto a world if you don't see elements of yourself reflected there. It's true of books, visual media, and games, any escapist media. It's why it's important to me to include LGBT characters in my fantasy worlds; if I can make the world, I'm going to make it reflective of how I think the world should be. So my games include gay characters, trans characters (both those with a deific blessing and those without), straight characters, asexual characters. I want to see a world where these things aren't an issue and where differences are embraced rather than reviled.
...and I'll shut up now. Hello, I'm happy to be here.