As a wedding minister, I find this couple's behavior deplorable.
So you think you should be forced with government guns to perform any wedding even if you find it objectionable? What if you knew the husband had been married five time and slept with the bridesmaid right before the wedding. Should you be forced with guns to perform the ceremony?
Before you say it's different, isn't the point that it's up to you what you consider moral?
As for me, I would totally bake a cake. I'd be uncomfortable however if I was a photographer. Not because I'd have moral qualms, but if it was guys kissing and stuff, I just don't want to see it. Shouldn't that be up to me?
Why should the State have the power to force any of it's citizens to do business with each other? Or as in the case of Jim Crow laws, force citizens to not do business with each other? It's an abomination to liberty