I've had this happen w/ a few groups--people will want to go to a restaurant for a cup of coffee, glass of wine or even share a dessert among a few. A couple of have said they'd just accompany and not order anything. I've always refused to go because it seems wrong to tie up a table for that but I'm always the odd person out. It's not Starbucks! What's the least you'd feel comfortable ordering? An appetizer? A shared entree?