That's why I no longer invite people over for dinner. It's awkward. On a positive note, I had a friend who was as vegan as you can imagine show up at a meat fest I was having one weekend. He bought his own portabello mushrooms and showed me how to grill them and make vegan burgers. He did the right the thing and I learned a lot. In your case, it's awkward. I'm sure you figured it out.