If I had to camp here, I would probably start with homosexualty/marriage being a choice and an action, not a state of being. Forcing me to participate in a type of union of which I religiously disapprove is demanding my tacit approval of something my system of belief does not accept. Conversely, serving a or more black customers does not require me to participate in blackness. Going down this tangent, serving a Black Panther function, with their overtly racist positions is another matter, just like requiring Jews to serve Nazis or blacks to serve the KKK.
I will also admit that I am not exempt from human nature. I get a lot more particular when I am the one getting kicked in the nuts.
Ahh so your qualms not with ideological consistency but that being gay is a decision you should be able to discriminate against?
That all said I highly doubt when anyone gets to Heaven God will give them grief for selling cupcakes to gay folks.
But that's just crazy religiousless me , thinking we should just treat everyone on earth with decency while we're here. After all an omniscient God might just confuse your basic human decency with a tacit approval for the gay lifestyle.