I suffered through their pretend marriage ceremony last year
Well, the deed has already been done. The "pretend" marriage that would become legal in hogwash MA would still be a "pretend" marriage in the eyes of God. The participants would be mocking God in fact. Your attendance would connote your "support."
That's why I don't think I could go. Their ceremony last year was NO fun to be at, especially at the point where they made a point of saying how much more they had to think about the committment they were making because of all the legal issues that are automatically dealt with for a legal marriage. I think my husband almost walked out of the room at that point. I felt like a hypocrite there - if they were to come here to "make it legal" I just don't think I could be a part of it. It would probably destroy my relationship with her, but it would be better for me not to be a part of it at all than to go and effectively support something I am so opposed to. Hell, even if they don't come here the odds seem increasingly good that this plague will spread quickly via judicial fiat.