Naked guy is wearing cock cage and his balls are bitten with clothespins during the fem dom education lesson
Black slave is cuffed to the bench and whipped by girls while his cock is clamped so he can't move at all
Dominatrix is wearing rubber gloves and dealing with slave's ball sack by using a set of medical clamps
Mistress is using balls destruction as a way to stop that man from jerking off: spread-eagle bondage, balls beating and trampling are doing the job fine