This little boy woke up three nights in a row because he kept hearing thumping noises coming from his parent's room. He finally approached his mom and said, "Mommy, every night I hear you and daddy making noise and when I look in, you're bouncing up and down on him."
His mom is taken by surprise and says, "Oh...well, I'm bouncing on his stomach because he's fat and that makes him thin again."
The boy says, "That won't work."
His mom asks, "Why?"
The boy replies, "Because the lady next door comes by after you leave each day and blows him back up!"