Goddess Nemesi wanted this guy to learn that she would not tolerate any nonsense from him and so she used her slaps to punish the crap out of him. He had never been slapped the way she slapped him and he peed his pants in the process. The mistress was categorical that he had to learn to satisfy her or else he would not get that chance again and he would regret it.
Goddess Nemesis wanted to punish this guy and she had to do it because he was insensitive. She did not want to deal with any insensitive asshole and so she had to slap the guy out of his insensitivity. He could not believe how hard and painful her slaps were and he knew he did not want to feel that way again. So he did what he had to do.
Goddess Nemesis did not want any opaqueness in any dealings she had with this guy. She had asked the guy to do certain things for her but he did not and she felt that he was testing her. She had to put an end to that nonsense and she did it with her choking as well as with her slaps. He had to feel pain to know that she was serious.