This was started because a number of children believed the lyrics to chorus of the Janis Joplin song "Piece of My Heart" were this:
"I’ll say come on, come on, come on, come on and take it!
Take another little piece of my hong yong, baby."
The children believed that this was a naughty term they just didn't know the meaning of yet.
Dude - you totally just pulled a hong yong, they say "Like a drifter I was born to walk alone"