[Dilly]

And also, what about the person who is in love with his/her animal and practices bestiality?

I'm not going to bother arguing the obvious point that animals are different from people, and I'll let you argue that opening up marriage to same-sex couples starts the slippery slope toward bestiality, but recognize that the slippery slope argument goes both ways. If the government can restrict marriage to only opposite-sex couples, then why shouldn't it also be allowed to restrict marriage to only same-race couples? Or same-age couples? Should the government be able to restrict marriage only to couples able and willing to procreate? And if a couple doesn't procreate as promised, then what, annul the marriage?

[FBFranco]

...but recognize that the slippery slope argument goes both ways.

I'll grant that it's indeed a slippery slope.

If certain people, pushing an agenda, had their way the census information would be collected: caucasian, black, American Indian, asian, homosexual.

It's not a separate race of people, but a very sad and disgusting gaggle.