Darling is bolted into the butt thrust frame and forced to exercise. This contraption forces the girls to walk with their backs arched and their asses thrust out in a provocative manner. It is certainly working here. Some electrics help to motivate her along her path.
Check out the sexy Natalie Minx in Demask's Inflatable Cover-All Top Straight Jacket. The think latex top inflates to the point of near breath control. Lydia takes the opportunity to use a crop and a flogger on Natalie's bare ass. Watch her forced to walk as Lydia encourages the exercise with repeated swats.