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.
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.