Katz, that's so extreme it goes into unreasonable. No one will ever accept bestiality as the norm, because animals cannot give consent. Incest has been proven to be genetically degenerating, so it will never be legalized either.
Homosexual marriage harms no one. Zero. Unless it negatively effects you in some way. And you'd be one.
But hey, you'd be given special concessions by liberals, who view minorities as special.
Current evidence would prove you wrong. Many enlightened countries already have legalized beastiality with Denmark having gone so far as legal animal brothels.
Animal brothels legal in Denmark | IceNews - Daily News
As far as incest does, really, get with the program. They can have sex without having children. Brazil, Russia, France, India, Sweden, Belgium, Portugal, The Netherlands and Japan have already legalized incest. Switzerland is considering legalizing incest as is Romania. Who are you to tell others who to love! With birth control and abortion the children of incestuous unions aren't even a consideration.
Once depravity is normalized, it goes all the way to the bottom of the barrel.