When Seva's slave is caught calling another Mistress, she and Cybill Troy decide to teach the lowly houseboy a lesson in manner, locking him into the stocks and a humbler, leaving him degraded and vulnerable for his punishment.
The two Mistresses viciously strike his trapped balls with their riding crops, humiliating and berating their slave for his indiscretion, threatening to take his testicles away if he doesn't start behaving.
She owns his balls.