WTWiz - It's an unusual situation because as far as i can tell, his main friends are non-witnesses. I just wondered if the 'not eating' thing in his mind makes him think he's still slightly loyal. He does not seem hard core, i think he does enough to get by at home.
Cameo-d - FOr most casual meals, we don't. Only when we sit down more formally. We wouldn't have anyone pray out loud if i felt it would embarrass a guest or make them feel uncomfortable.
Hamster: That's a great Scripture in your reply; it assumes the Christians would be eating with worldly people. Also the reference to associating with "worldly" people in I Cor 5.
Thanks for the interesting answers.