We used to have wonderful "pitch-in dinners" at our church when I was growing up. People would bring their particular specialties....the best fried chicken in the world, the most wonderful chocolate cakes, etc.
Our next-door neighbor and her family would only eat what they had brought. There they would sit, with nothing but green bean casserole or ham slices or whatever it was that she had made on their plates. Her explanation was "I don't know what kind of kitchens the other food was prepared in", which is pretty insulting in my opinion.
What would even be the purpose of coming?
