From the song, "Shapoopie," as seen in "The Music Man," a play about a man from Gary, Indiana who makes a boys band in Iowa and falls in love with a librarian.
Shapoopie, shapoopie, the girlthat's hard to get.
Shapoopie, shapoopie, but you can win her yet.
The act of shampooing one's pubic hair while taking a morning shower. This is used to cleanse the pubes of oils or unwanted semen from the night/morning; thus, the pubes are now free to sway to and fro in the wind.