Spiritually speaking, is it possible to be in favour of gay marriage, but opposed to the couples having kids?

I don't think so because most of the time marriage involves kids. Who are you to say that maybe those gay parents wont be good parents?? I've seen so many heterosexual couples who are just horrible parents. I'd rather see a happy family (even if the parents are gay) than to see an unhappy family. Also what if there's a kid who is being taken care of by his mom and aunt or by a mom and a grandma (two women)... Would that be wrong too??