One time we went to a Thai restaurant. We sat next to an Indian family with a young girl. The girl and my dauther are about the same age. We're happy to see the family and we smiled at them. After we sat down, we chatted with the young girl for a little bit. Then we went on our own ways. They left the restaurant first, just after we finished ordering our desserts.
When we're done with our dinner and asked for our bill, we're told that family already paid it for us. We're so surprised. They didn't say anything to us before they left. We didn't even have a chance to say "thank you" to them.
It's such a nice gesture! We felt very special:)