As someone who enjoys psychological stories, here's my opinion.
This covered a lot of good aspects and failed miserably at the rest.
For one I liked having his inner thoughts and the artist did a good job at visualizing his despair.
Also the details about noticing his brother and freezing up which is a common reaction in victims of abuse.
Same with becoming less resistant and loosing strength at the mere touch of the abuser.
You become paralyzed and fear for your life.
I liked that the conclusion didn't involve the younger brother falling for his abuser and actually ended rather sad (loosing the only person he wanted to open up to).
In that aspect it was realistic and a good depiction of the decaying mental state of a victim of abuse (especially the sexual kind).
Now onto the bad aspects, unfortunately this turned into another work that romanticizes sexual abuse.
There was no need for the graphic sex scenes.
They felt like smut meant to be enjoyed by the reader.
I get wanting to show the reality and scope of the abuse happening but why did it have to include a close up of the brothers dick penetrating him?
There are far too many of those and leave a bad aftertaste.
You can realistically show abuse, for example "A cruel god reigns", severe case of child SA but it never showed it directly, just glimpses into the horror of what the protagonist had to endure.
Accompanied by his inner thoughts.
It's unfortunate because this story had good writing on the inner monologues.