As Celeste looks at her ex-husband staring at her, she can't help but feel anger at this person because of the many assassination attempts she had had to overcome.
Celeste indeed had cheated on him many times with dozens of different men. So, she did not feel she had the right to judge the hatred this man felt for her or even question him for the many assassination attempts.
It was only natural that this would happen. After all, they were supposed to be monogamous. And Brooke's father followed this religiously, never having touched another woman since he met Celeste!
But Celeste had broken the taboo, done something that even polygamous people would not accept, cheating on her husband.
That is because people in polygamous relationships had to receive the consent of their partners to have sex with others.
That was true for the man as well as for the woman. Though men rarely agreed to share their wives with others.