Missed Connection

So I have some complaints today:

This afternoon, I was at a group meeting finishing off an assignment, with a group of people, putting up with their homophobic, anti-woman jokes. The one group member and I got into a bit of an argument regarding the church stance on gay marriage. She was convinced that its not fair to ask priests/pastors/ministers to perform a marriage for a gay couple, because their religion is against it. She likened this to asking Muslim women to take off their hijabs. I tried to explain though that this church discrimination is against the way someone is born, and therefore plain and simply wrong, but the group was convinced that homosexuality is a choice. Due to the fact that we were working on an assignment for later that afternoon, the discussion had to be dropped, but I wanted to ask them when they chose to be straight. I wanted to ask why on earth they think anyone would ever EVER choose to put themself into a marginalized group? Why would anyone choose that for themself unless its who they are? I never chose it. I realized it. Being in relationships involve choice, but who you fall for does not. It doesn't in heterosexual relationships, so why would it in homosexual relationships. This makes no sense.
I don't know what to make of this. I wish I could have argued. I wish I could fight each one of these battles. And it feels like I've failed when I miss one. Shoot.
Thoughts?