Oxford English is behind the times & a follow up

For my playwrighting class, I am writing about a translator who is also going through a gender transition. The play is mostly about the imperative to tell her mother about her transition, but I'm having a lot of fun playing with the levels and parallels available in making the character a translator as well.

The Oxford English Dictionary (OED) is one of my best friends. Yes, I'm a loser who can spend hours hitting the "learn something!" button on the website (though most of the time discovering that I know the word they're showing me.) So I looked up transsexuality for a speech in the play. Their definition? "loosely, bisexuality."

This bothers me... a lot... though it might go some way to explaining what the hell was going on with these guys that I ranted about before. It bothers me academically because I feel that people who run a dictionary ought to know better. It bothers me personally because I had, up to that point, put full linguistic trust in the OED. Proving once again that you shouldn't believe everything you read...