A whopper bopper is a girl who loves to give head in trade for a so called whopper as in the burger from burger king so in short terms she would suck your dick for the trade of food
This is closely related to the Houdini. In this act, you are doing a girl from behind. Upon climax, you pull out and explode on her back. When she turns around to see what happened, you yell, "Whopper Jr. Bitch!" and hit her in the face with a Whopper Jr. hamburger. (Cheese optional)