A mother took her three little daughters to a mall to do some Christmas shopping. While they were there the three little girls had an opportunity to sit in Santa Claus' lap and tell him their wishes for Christmas. When they had finished, Santa Claus asked them, "Will you do something for me on Christmas morning?" 

And they said, "Yes!"And Santa Claus said, "I want you to sing ‘Happy Birthday' on Christmas morning?" The little girls were surprised by this question and said they didn't know of anyone having a birthday on Christmas.  Their mother, who was standing by and listening to the conversation, said, "Come on, now, who's birthday is it on Christmas?"

One of the little girls suddenly remembered and exclaimed, "It's Jesus' birthday!"

Santa Claus said, "That's right, so you be sure to sing Jesus 'Happy Birthday' on Christmas Day." And then he gave them each a kiss. A few days later the two youngest of these same little girls went to another mall and had a chance once more to sit in Santa Claus' lap. When they returned home their eldest sister asked, "Was it the real Santa Claus?" Again, their mother overheard this question, and asked, "How do you know if it's the real Santa Claus?"

And the little girl said, "The real Santa Claus tells you to sing ‘Happy Birthday' to Jesus and gives you a kiss."