OK, how about...
You have a business creating custom cakes. You could, for example, make a football cake for a boy’s birthday party, or a cake that looks like a pony with a pink hair ribbon for a little girls party, etc. The sign at the door says “WE make custom cakes! Tell us what you want us to bake, and we’ll do the rest!”
Someone comes into your store, and asked you to make them a cake that looks just like a vajiji. Do you have to? How about a man’s phallus? A couple doing a sex act? I’ve seen these cakes. But do we really get to sue a bakery for NOT making them?
I hope not
This Happened! I am not sure if you are being sarcastic referencing this incident.
Oregon ruling really takes the cake -- Christian bakery guilty of violating civil rights of lesbian couple
http://www.foxnews.com/opinion/2014/01/21/christian-bakery-guilty-violating-civil-rights-lesbian-couple/
If your sign states you will bake anything and you then decline to bake something that offends you they could sue you for false advertising.