Okay, all those that support legalizing gay marriages, please check yes or no on extending it to the following types of relationships/behaviors as well:
a) Incestual: Brother marries sister, mother marries daughter, mother marriers daughter..etc
b) Pedophilia: Age of consent is, after all mostly a reflection of a particular societies moral values (by the way, moral doesn't automatically mean religious). So how about a 50-year old man wanting to legally marry a 12-year old girl?
c) Polygamy (been mentioned already, of course)
d) Adultery (also mentioned, and rather eloquently)
e) Beastiallity: Of course, you'd need to somehow prove the goat enjoys it.
Every arguement made in support of gay marrieage could be made about the above behaviors. Yet, many of you who support gay marriages find at least one of the above behaviors as abhorent and deviant.
You need to go back to the reasons marriage has been legally codified in almost every society/culture on earth. It isn't simply to make to people feel better. It stems primarily from the need to stablize the relationship of a man and woman, in order to insure the children they bring into the world are taken care of. I also think it was influenced by factors associated with the differences in roles men and woman played when societies were young (i.e. primary provider vs. child-bearing/rearing roles). Religion also played a part, but the idea of marriage predates most if not all organized religions.