Check out this article that acknowledges both sides of the gay marriage debate.
My thoughts to you, Michael, are that you seem like a relatively smart guy. I think your answer is right in your own words:
"However the Church maintains that male-female martial bonds invoke a unique relationship that simply cannot be met by a same-sex relationship."
The church MAINTAINS??? The church wouldn't have to "maintain" anything if it were actual fact. They "maintain" that stance because they know that they have no proof. And come on, not ALL heterosexual sex is about love and procreation..a lot of it is just about fucking. Believe me, I've been there.