Wee Willie was walking past his parents’ bedroom in the middle of the night, in search of a glass of water. Hearing a lot of moaning and thumping, he peeks in and catches his folks in The Act. Before dad can even react, Wee Willie exclaims “Oh, boy! Horsie ride! Daddy, can I ride on your back?”
Well Daddy, being a little relieved that Willie’s not asking more uncomfortable questions, and seeing the opportunity not to break his stride, agrees. Willie hops on and Daddy starts going to town. Pretty soon Mommy starts moaning and gasping.
Willie cries out “Hang on tight, Daddy! This is the part where me and the delivery guy usually get bucked off!”

Author Unknown