i witnessed something beautiful

I’m a waitress at nigh to earn some money during the vacation. One night there was a mom and her son, he was still little but big enough to walk on his own and it seemed like he had some sort of mental disability, like autism. He and his mom walked around and she was very caring with him. They walked past a table with an old couple. The man had grey-white hair, a beard and a very round figure. The mom and son stopped at their table and the grownups conversed while the boy kept putting his hand on the man's arm, even though his mom kept taking it off. The little boy was very persistent, though. Not aggressive but gentle. Finally he accomplished what he had been trying; to move the man's arm from the table to his side. Almost like opening a gate. Then the boy climbed atop the man's lap, "He thinks you're Santa Clause" the mother explained with a smile. The man then simply gave the boy a hug and laughed. From the boy's expression I could see he truly believed he was sitting on Santa's lap. Even though i'm not a big fan of Santa that moment was beautiful. It really touched me.