Really mean it is when the slave knows that he will be used for hours by the mistresses, even meaner it is when the mistresses make him directly so horny that he must cum. But the meanest thing is that he then also has to eat his sperm and that where now his horniness is gone... Well and unfortunately that was only the first 10 minutes of his treatment and the slave becomes painfully clear that this will be a very hard day for him.