I agree this is a problem but it’s not an insoluble one. Fr. Z had a good idea. If one or more of these people ask you to cater their faux wedding just politely say you would rather not for religious reasons. If they decide to be dicks (pun intended) about it then say fine. We will cater your bash and we will do a great job. We will charge our normal rates. And when it is over, every penny above the base cost of the service will be donated to the Family Research Council (or fill in your favorite charity guaranteed to make their heads explode) and it will be done in their name. And we will take out a newspaper add publicly thanking them for their contribution.
I strongly suspect that this would effectively end the problem.
Back somewhere in my posting history I have posts putting forth this same idea of assigning the proceeds of a homosexual wedding cake to promoting traditional marriage.
I think that the idea may be subject to discrimination laws, because homosexual cakes are singled out. Don’t know, it’s a legal question, and I’m not an attorney.
The easy workaround, however, is to donate a fixed amount from all wedding cakes to those causes.
Here is to kicker; Encourage matching funds from non-business sources, friends, churches, customers for cakes of their choosing.
Business contributes $10 per cake (let’s say), others match it at 10:1, or some amount of their own choosing.
Suddenly, thousands of dollars are raised, the community is involved, and, as nearly as I can determine, no laws are broken.