This question already has an answer here:
Related and a follow up to this M.Y. question:
The U.S. Supreme Court has legalized gay marriages in al states. There have been several publicized law suits in a few states where a gay couple sued a caterer that refused to cater a gay couple marriage because the caterer stood on religious principles. In all these publicized cases, the caterer lost the suit and in at least one case, had to pay damages. As far as I know, all these gay marriages were Gentiles.
My question is focused on these aspects:
In viewing the answers to the linked question, it seems that halachically, Noahides have accepted the prohibition of gay marriage. It is unclear how Jews should should enforce these rules.
Va'adei Rabanim have had a practice of using the owner's adherence to mitzvoth as criteria for certifying a place. (E.g., many Va'adim will not certify a kosher establishment if the owner is not Shomer Shabbat, even if the food is 100% kosher.) I am uncertain as to why this plays a factor as it doesn't seem to have anything that directly affects the kashrut of the food. This is another aspect of my question. I.e. - IF a caterer decides to cater a gay marriage affair, halachically, MUST or should the Va'ad revoke the kashrut?
Din Demalchut may play a role in these cases, eventually at the point that a gay couple files suit against a kosher caterer. If there is no direct halachic basis for a Va'ad to revoke kashrut based on #2, would the Va'ad have to halachically allow caterers to cater to gay couples and furthermore require that they do so to obey Din Demalchut to keep their certification (in a sense, the opposite effect of #2.)
Is there any difference in the criteria if the caterer performs a Gentile gay couple affair or a Jewish gay couple affair?