They have a really interesting logic on this one - It's not a sin (anymore) because (now we understand) God made them that way and it's not their fault that they're gay, it's just that this is their trial in life and they have to make the right choice to not be gay, because God is fair, and...
I couldn't resist asking HT about this: if you live in a state that recognizes gay marriage, then surely, you have the right to have sex with your legal spouse. What does the church say about this?
HT hemmed and hawed, turned a fascinating shade of eggplant (or aubergine, if you are in the UK), and said he was pretty sure that the Prophet would hack up a revelation about it sooner or later. Well, he didn't put it quite that way, but that was the substance of it.
They don't know what their opinion is until the church tells them.