The Pleasure Pain Principle

Mistress Sidonia initiates one of her scientific experiments, with the unwitting help of her slavegirl and slaveboy. The slavegirl is commanded to keep the slavboys cock hard by whatever way she can, she keenly uses her tongue and mouth on the lucky slaveboy. Mistress Sidonia then introduces the pain element by beating his arse with various implements, thus linking pleasure and pain in the poor slaveboys simple mind. To reinforce the conclusion, the slaves are ordered to fuck each other, with the Mistress continuing to punish the slaveboys already deeply reddened arse cheeks.