Yep, I’m sure they wouldn’t, so no matter how polite I am and whether I explain (or lie?) declining will come as a rude shock. I really did want to avoid that, but I guess there’s just no way around it. Either I offend them or they offend me. Oh well.... that’s life hey?
Now I have thought more about this issue last night and today, I think next time you are invited, if declining, maybe do so without a reason. Unless you know the parent well enough to know that they won't be offended by your beliefs.