Oddly coupled

Witches and their spouses are failed social contortionists. One time this witch and her husband were trying a new social game and he had his nose too close to her rear end and she stepped back, most people believe on purpose, but he hadn't anticipated her back tracking, so now they go together everywhere like a human centaur, the witch walking upright, her husband with his head stuck up her ass bringing up the rear.

-SDG