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.