Lady Emerald found out that her slave had messed up and had gone against her wishes. So she set out to punish him. The mistress whipped one of his butts after she had stripped him naked and she had tied him up so that he would not resit whatever she wanted to do to him. She wanted to make it extremely painful so she just concentrated on one butt and whipped it mercilessly.
Madame Marissa is a strict disciplinarian. She had a badly behaved student and she tried to talk to him but he did not change. The mistress felt that he needed a stronger punishment so she used her cane to do it. Madame Marissa caned him painfully and she made sure the student was in a lot of pain so that he would never be tempted to behave badly again. It worked.