Lunch with Mom

I met my mom for lunch by the mall before Christmas. We sat in a booth across from a man sitting alone in his own booth. When we got up to leave, he said to the waitress, "Give me their check—I'm going to buy them lunch." Then he told us, "I wasn't trying to eavesdrop but what I heard was the most intelligent conversation I've heard since I came to Utah in 2003." (Been out much?? haha) Then he said, "I tried to figure out your relationship and thought you must be mother and daughter, but then I thought, no, I don't think they are. They're best friends."