a vehicular seat assembly includes a seat bottom defining an occupant seating area . the seat bottom includes a cushion covered by a trim cover spanning opposed lateral sides of the seat bottom . a seat back defines an occupant back support and includes a cushion covered by a trim cover spanning opposed lateral sides of the seat back . an opening is formed in the cushion at one of the lateral sides of the seat back . an opening is formed in the trim cover at one of the lateral sides of the seat back . a cup is received in the opening formed in the cushion . a retaining ring is secured to the trim cover about the opening formed in the trim cover and attached to the cup .