My cousin had this favorite joke when we were kids and now i finally understand it!

This lady gets on the bus with her liitle dog whose name was "Itchy-Boom-Boom." It was a nice day so the bus windows were open, and all of a sudden the little dog jumped out the window. The lady started yelling, "oh my itchy boom boom! Oh my itchy boom!"

The bus driver turned around and said, "so whyn'tcha itch it, missus?"