Step #1...accept the job.Step #2...don't require any payment until after the "ceremony".Step #3...make sure the cake,the photography,the flowers are so abysmal that the perverts express their outrage and refuse to pay the tab.Step #4...apologize profusely (of course you won't *mean* what you're saying) and agree that of course they need not pay.
What you've accomplished is that it's guaranteed that no pervert "couple" will ever again want to use your service.
But it does not do anything to reverse the societal attack.
Flaw in your thinking: most male florists are gay.