Pro homosexuality. And homosexual myself. Although I am pleased to see so many here who are "straight, but not narrow" (as the Tshirt goes).
I laugh like a drain whenever someone mentions Leviticus - Shellfish? Mixed fibres? Selling people in to slavery? How is that working out for you? Or do you only do the "treat GLBTQ people like shit bit?" What about loving your neighbour? What about not judging? What about all that doing unto others malarky? Or do each of those teachings (and the general overview of the bible being "don't be a dick") have an "except for the queer folks" clause on the end?
And, although I don't bother myself any more, the point of Pride (which a few have mentioned here) is that, just for a day or even just a few hours, it is nice to be in a place where you are no longer a minority. Unless you have felt that, I'm not sure that you will understand. I was born in a small town, I didn't know where the other GLBTQ people were and I didn't have a way to get to them. And one day I went to a Pride and suddenly they were everywhere. It was nice not to feel so alone any more. Plus, in many countries, Pride is still a political movement to bring about safety and rights under the law. Please understand that the float full of twinks dancing in white underwear is just the bit that the media wants you to see.
All we really want is equal rights under the law. I'm old enough now to not really give a crap if someone doesn't "like" me. But no one should be spitting at me, wanting to attack me, wanting to verbally abuse me in the street. Maybe I do look like a stereotypical butch dyke, but it's just funny how those things work out. And yes, maybe I do wear a small pink triangle pin or a rainbow pin or a labrys pin, mostly in remembrance of others. But what I won't do is sit in the closet in case my presence offends someone.