"I will choose to kill them both!" She made up her mind and said it aloud for Minos to hear.
For Abby, a betrayal was something unforgivable, and if any of her harem sisters did such a thing, she would kill such a person herself!
For her, nothing was more significant than her love for Minos, so she could not forgive the idea of an adulteress by his side.
A woman who cheats on her husband was not only someone who did not respect him, who despised him and cheated. She was also someone who brought risks into the home. For example, what if the lover decided that the adulteress' spouse was getting in their way and his death was the best thing?
Not only that, there was the risk of pregnancy, bad influences within the home, etc. In addition, a person who cheats would typically add one or another custom of the lover, which could negatively affect the dynamics of a family.
I don't defend what is in that chapter, just as I never defended the content of the novel. I'm just showing you the logic of the characters.
I think most of you understand this, but every now and then a reader writes posts as if I am defending these behaviors in the real world.
Absurd, only an immature person would allow themselves to be influenced by a novel and confuse fictional content with real world opinions.