One day, little Johnny asked his father, “Dad, why do grown-ups like to exercise in bed?”

His wife, who was cooking dinner, overheard the question and decided to eavesdrop on their conversation.

The father replied, “Because it makes grown-ups happy.”

Johnny said, “I want to be happy too.”

The father responded, “Then you have to wait until you’re a grown-up.”

Johnny asked, “But who will exercise with me when I grow up?”

The father said, “Hopefully, when you get married, it will be your wife.”

Johnny then asked, “But Dad, how come our neighbor Sally exercises with you?”

The wife rushed out of the kitchen, and an ambulance arrived 10 minutes later.