Of course, homosexual relations are a sin according to Islam. But theoretically, civil (nonreligious) "marriages" do not have any standing in Islam. So is there any reason to oppose the legalization of homosexual marriage (suppose in a secular country like the United States) which is really no more than a contract allowing the person's "spouse" to visit him in a hospital, file joint tax returns, etc.?
Furthermore, assuming that some Muslims happen to live in a place where such marriages are legally allowed, would it be permitted for two unmarried, male Muslim friends to go to a New York courthouse and "get married" so that they can get the tax advantages and hospital visitation rights that come with such a status? This is all assuming that there is absolutely no romantic interaction between the two of them?