
Honestly I would be creeped out (putting it very lightly) if I had a family member who has such thoughts.
Even in this case, even if the brother doesn't know what he is thinking and did not act on it, who's to say he won't actually act on it in the near future. The way it's described in the introduction implies that has some serious issues, and needs to be locked up away from the brother.
I don't understand what author is thinking. This is serious rape fetishism.

If you know about UX which means User experience, anything which follows the flow does not stand out. If you want something to stand out make it different. The uploaders has three warning pages, which actually follow the same theme. Pink with blue text. It's not glaringly obvious and also since most uploaders put warnings of not uploading the work somewhere even for the manga which seriously need Trigger warning, I have long since stopped reading it. That's the reason I was advocating for a separate section for Trigger Warnings which is glaringly obvious (if you have not seen the other comments).
Secondly, I no where said anything about the uploader, forget about complaining.
And I put a Trigger Warning when I comment on a work which needs these. Nothing specific about this work. It's my freedom, I don't see how that is causing you any pain.
Coming to the title implying incest, I was actually condemning the child rape (fetishism) part, and that too from a family member. No where did I talk about other cases of incest/ half-incest/ adopted incest etc. That's a different topic altogether.
And finally, there is something called as leaving an opinion in the form of a comment and condemning wrong things, may be read about it?
Trigger Warning : Rape, Child Rape (since they are in school), Incest
Just plain disgusting. Couldn't go past Page 5. Disgusting family like this is enough to ruin a child's life.
Also, again with the one brother having black hair and the other having blond. And somehow the blond is being abused. This is a recurring trend in BL. Light haired uke stereotype ensues. Twisted case of Racial domination and fetishism.