Well, here’s the other thing. I think sexual reproduction is an evolved trait (not all organisms reproduce sexually), and while sex is advantageous to be sure, I don’t see anything in nature that suggests some divine dictate so all sex must be procreative. You certainly see examples in the animal kingdom, particularly among other Great Apes, of sexual activity that does not have a procreative component.
So if God can tolerate a couple of female bonobo chimps having a same-sex encounter, I’m sure God is a big enough fellow to be able to tolerate John and Jeff getting hitched.