A reference to a song by Parliament-Funkadelic leader George
Clinton. Which in turn was referenced in the 1997 children's film Good Burger. Sometimes the phrase is mistaken to be a sexual reference, but it is not. It instead references combo meals at fast food restaurants. The phrase is a male asking a
woman to go on a date. So instead of just being a solo shake, a reference to feminine hips, he's asking as a hearty spud himself if they can be a combo.
Due to the
joke's fast food theme, it implies that the male is asking to take her out to lunch.