JGC:

After all, homosexuality has been observed in all cultures throughout all of recorded history, as well as in non-human populations—how much more natural could it get?

1. It could be mentioned in the Bible without associated mentions of abomination and rock throwing etc.

2. It could result in pregnancy.

That's all I can come up with. Sounds like it is on a par with adultery. Except that could result in pregnancy...ah never mind. Anyway, Adultery is in the 10 Commandments and homosexuality isn't.

So I think the message is clear. Either gay marriage and adultery are both legal or both illegal. Can't split them up arbitrarily.