Knock Knock

This morning on one of our morning shows (the Backyardigans) they were saying knock knock jokes. After they were done, Tyson came up to me and said, Knock knock. I said, whose there, he replied, peanut butter (bear in mind this one was not on the show). I said peanut butter who? He said peanut butter and jelly. It was so cute that he made it up himself, and he thought it was HILARIOUS!!!