Ok that is very bold, I think my comment would be more to the PastorI would go and give an objection when the pastor asks if there is any just reason why they shouldn't be married. I'd say that this marriage is a farce and an abomination, and that having sex with your same gender is unnatural and disgusting. THEN I would say, you need to stop and repent of this lifestyle, and cancel this wedding forever.
And then I'd leave.. lol