That's a knee-slapper!

Lately, there have been lots of knee-slappers being told around our house. My mom taught Ryder the phrase last week and since then he's been using it all the time. He understands that it means something is a joke and is funny because he always uses it appropriately. Whenever someone says something humorous, Ryder says, "That's so funny! That's a knee-slapper!" while at the same time actually slapping his knee. It's just too cute!