When this loser tried to lie to his mistress, she did a little digging and found out he had lied to her. Whenever she is given certain information, she likes to check it out to find out whether it is legit or not. When she realized her slave had lied to her, she punished him in an effort to send a message that she would not condone that kind of behavior again. She facesat on him and trampled him hard.
Princess Serena wanted her slave to know which side of his bread is battered. She had noticed he was beginning to lose his sense of direction and she wanted him to get back his focus. So she punished him to get him back in line. She facesat on him while wearing her jeans and she used it to humiliate him. It was extremely painful and made him learn his lesson.