Nancy and Jonathan get Steve to drive them for their date, except instead of going for dinner or a movie, they have Steve pull the car over and then they have sex in his back seat, telling Steve he's not allowed to turn around or look in the mirror. He just has to sit there and listen to them. They get off on him being there. He gets off on hearing them (if he's allowed to). Then he has to drive them home.
Jonathan/Nancy + Steve, Sex chauffeur/back seat exhibitionism