Gay Marriage

I've just had an interesting thought regarding gay marriage. Has anybody come up with a coherent secular reason for why homosexual couples shouldn't be allowed to marry, or at least receive the same tax breaks that heterosexual couples? Religious arguments can be used to both undermine and support gay marriage, but I really can't think of a single argument against it that isn't based in religion. I could be wrong, and I'd love to hear such an argument, but I fail to comprehend what it would be.

Economically speaking, legalizing and legitimizing gay marriages would no doubt pump a decent amount of money into the wedding planning industry, as well as retail shopping for all the gifts, and tourism for the honeymoons. Especially in the beginning when there would no doubt be a surge of couples looking to "make it official."

Also, since these couples couldn't really have offspring of their own, not without expensive genetic technology anyway, they would resort to adoption if they wanted to have kids, a family, and I'm all for more loving homes for children to be adopted into.

I don't really think that any arguments against gay marriage that involve instances of failing marriages, or harm to children, or anything like can really apply, because all those arguments can be used against straight marriage too.

As a country, we can't espouse equal rights for all if we're going to institutionalize unequal treatment under the law. It is our destiny to provide equal and protected rights for all of our citizens, regardless of skin color, gender, age, religion or sexual orientation.