I later realised that something like a sketch or column wouldn't be theatrey enough, and I didn't want a play about homosexuality, but rather, a play with a gay character.
I ended up adapting a monologue from a short play by Alex Broun titled The Gift Of The Gun. You're welcome to review my version and send feedback:
http://files.jones.id.au/posts/2009/gun-monologue.pdf
I don't know if it's particularly funny, but I think it should be okay. Now I just have to learn it and rehearse!