I think the Gay marriage thing is just a validation thing. They want respect that is all and very few of them actually want to be "married".
(Denny Crane: "Every one should carry a gun strapped to their waist. We need more - not less guns.")
The same-sex thing is just about rebellion against God. God is the One who created marriage and procreation therein. Homosexuals are acting out their disbelief ie. hate of God when they claim same-sex attraction.