The kid was taken in not the mother! The fault lies with the adults who took no action to communicate or give up their selfishness (husband’s affair, grandpa’s want for nobility, and in a way the mom’s denial of reality). It’s clear that the kid wasn’t ill-intentioned when opening that door nor was it shown that he harbored hatred toward any of them. While not in the same extremity as ML, he also lost his father, his stability, and his entire understanding of life and love. It’s not a kid’s fault for being born; it’s the adulterers’ faults for being awful. And, this kid wouldn’t have even been a problem if the Grandpa had agreed to end the marriage. I understand why Grandpa felt responsible.
Nonetheless, I agree that the grandpa really didn’t have to bring him in to be ML’s friend though. Genuinely insane line of thinking- having ur dad’s affair kid who is literally only a few years younger than you become your playmate can ONLY sow more hate
Why on earth did he take him in? Should have left him with his mother and let them rot. The Duke not only lied to the grandfather on the wedding day, that he broke things off with his girlfriend. He moved in his lover and their bastard son on the Ducal grounds in full view of the Ml's mother. But did it so brazenly in front of his wife and have a parallel family with another woman next to their home, it drove his wife to a nervous breakdown and then suicide. So despite this, and seeing how traumatised the ML became not only from realising his father had kept another family on their estate and had betrayed his mother. But also seeing how such a betrayal led for his mother's mental sanity that she killed herself.
The ML says himself he never considered his brother "family" so why did the Grandfather keep him in their lives and fund his upkeep? He is part the reason the ML's mother is dead.