Responses
I read again the second son story (never knew the trash of a story is actually in league with these two new updated manga). And since I didn't read the novel, I think we hate the second son because of the poor adaptation by the mangaka. Or the second son is really toxic.
The MIL is unredeemable tho
After having read the other two stories in the series, I read the third one and the MIL has turned into a human being after being almost as toxic as her middle son. The FL's father, however, has taken their places as the self important butthead of the universe. Not to mention that he's a total bootlicker for all the people in his SIL's family.