They can't define it for me, regardless of what the law says. Mine is a sacrament, and a covenant, and would be with or without legal sanction. If they want legal sanction for theirs, that doesn't define mine.
So what's the problem with the FMA? If marriage is between a man and a woman in the law, its not an act of bigotry against any one else. I defy any one to show me how centuries of heterosexual couples being happily married have made gays and lesbians feel excluded.