If two adults wish to use each other's large intestine as a sexual organ, fine. Whatever. Let the ensuing disease and madness be on them. But why must I or anyone else be obliged to give it our consent and approval?
Unless you extend positive, approving acceptance you are an oppressor, didn’t you know that?
Well, one of their “rights” is for you to sit idly by as the institution of marriage is turned into a circus. You must do so without so much as raising an eyebrow, otherwise you are infringing on their right to equality.