A seat belt positioning mechanism that has a vehicle seat and an elastic tensioning member. The vehicle seat has a frame structure, a cushion portion covering the frame structure and a cover material covering the cushion portion. The cushion portion defines a main seating section and an outboard side seat section extending laterally outboard from a corresponding side of the main seating section. The side seat section defines an opening extending through the cushion portion. The opening is dimensioned to receive a seat belt extending therethrough. The cover material has a cover extension extending into the opening. The elastic tensioning member has a first end fixed to the frame structure and extends under the cover extension into the opening. The elastic tensioning member is dimensioned and shaped to bias the cover extension in an outboard direction against a part of the seat belt located within the opening.