I understand your point, but think of it this way. If you are an evil horrible person what is the best way to hurt someone? To take away what matters most to them. What mattered most to him was his brother and he didn't want him to know about that part of his life so that's what the guy thought would hurt thin most. But thank God they were interrupted.
True, it was uncomfortable to read but that guy was smart enough to make the most disturbing move.
What was more uncomfortable was that the author didn't address the emotional trauma of the younger brother. Even a group hug could've eased the bothered minds of the readers.
The little brother thing was so uncomfortable and unnecessary.