1. Gays are promiscuous, .......

The reply here for me is obvious. Divorce is already common, isn't the institution of marriage already getting tarnished? But why would a gay person be more promiscuous than a straight person? From what I can tell a gay couple is just as likely to have a long-term relationship as anyone else.

The "traditional" side of me feels like it is too bad that we are reduced to mounting a defense of a particular lifestyle based on the fact that the institution of marriage is tarnished and that divorce is common. Wish these weren't so, but they are. Secondarily, I'd say that there *are* aspects of gay culture that are promiscuous and that it is perhaps considered impolite to mention (Hey, some guys fly R/C airplanes, other guys are obsessed with mobile MP3 players...) but that your ultimate conclusion is correct -- gay folks are as likely to have a stable relationship as anybody else...

2. Homosexuality is against nature and God, so gay marriages shouldn't be supported by the government.

Animals have been known to engage in "homosexual behavior". Animals are a part of nature. Humans are animals, too. And this is by no means a new thing. In ancient Greece and Rome it was actually expected for a young man to take on an older more experienced "tutor". As for God, supposedly the good old U.S. of A. has seperation of church and state ... but that's never stopped us from bringing religion in to politics before.

This is hard to argue against if you are not on board with the whole deity concept. Plus, even if you are, there's no guarantee that your deity will be as pure and strict as *their* deity, so someone's argument that "X" is "against nature and God" can always be held as valid in their eyes if your vision of God is perceived to be deficient..

With respect to "younger men taking on older more experienced tutor/s" memories of Mary Renault's excellent historical fiction "The Last of The Wine" comes to mind, but it doesn't seem to provide much of a useful justification/defense. Nowadays, invoking ancient Greek social history seems to conjure more of the unsavory NAMBLA, predatory-priest imagery that we wish would go away... .