More According to Andrew

"Once you have accepted that there is no moral difference between homosexuality and heterosexuality, the arguments against same-sex marriage collapse. And since the only coherent moral difference is the likelihood of non-procreative sex, and that is now the norm in traditional heterosexual civil marriage, there is no moral case against allowing gay couples to have civil marriage. The rest is fear and prejudice and religious conviction. None should have a place as a legal argument in the courts."

Then there is no argument against marrying one's close relatives either, as long as one does not have children with them. At the very least, homosexual incestuous marriage must be allowed, as inbreeding would not be an issue.

That is all.