Partyboy is an Exotic Dancer from the TV show Jackass and Jackass: The Movie. He is also known as Chris Pontius. :]
Chris Pontius goes by Partyboy, Chief Roberts, Roller Bobby, Bunny the Life Guard, Strongman, and Garbage Man.
The song is 'Partyboy, What is the Secret of your dancing?' and it has another version called 'Wonderboy'.