What scares the dickens out of gay marriage is not the gay sex but (which is natural for people born gay through epignetics, no one choses it) that no one is in charge. The Christ as bridegoom model has the hierarchy stand in for the husband with a subservient laity. No one is subservient in gay marriage and no one should be subservient in the Church either (except for the hierarchy - or have you forgetten Holy Thursday's washing of the feet already?).