The girls have sweaty feet after two hours in the gym, they know that Jack hates feet so they decide to make him smell his socks and lick his feet, he has to clean with his tongue the sweat and the soles of the 6 feet of his mistresses who are taking turns, they also step on him doing trampling and facesitting.
When the girls think they have his feet clean and have humiliated their submissive well, they gag him with adhesive tape and tie a sweaty sports shoe from the gym on his face, with a harness from which Jack can not remove it, the girls leave the room and leave their submissive tied and gagged and with the shoe on his face, every breath will be stinking for Jack and every second a punishment for his sense of smell.