At school, Little Johnny's classmate tells him that most adults are hiding at least one dark secret, so it's very easy to blackmail them by saying, "I know the whole truth." Little Johnny decides to go home and try it out.
Johnny's mother greets him at home, and he tells her, "I know the whole truth." His mother quickly hands him $20 and says, "Just don't tell your father." Quite pleased, the boy waits for his father to get home from work, and greets him with, "I know the whole truth." The father promptly hands him $20 and says, "Please don't say a word to your mother."
Very pleased, the boy is on his way to school the next day when he sees the mailman at his front door. The boy greets him by saying, "I know the whole truth." The mailman immediately drops the mail, opens his arms, and says, "Then come give your Daddy a great big hug!"
When Santa came home, his wife, Jeeto, was crying.
"Your mother insulted me," Jeeto sobbed.
"My mother? How could she do that when she is on vacation on the other side of the country?" Santa asked.
"I know. But this morning a letter addressed to you arrived. I opened it because I was curious."
"At the end of the letter it said, 'Dear Jeeto, when you have finished reading this letter, don't forget to give it to my son.'"