I think the step-younger brother is delusional, very impolite, highly self-centered and his cockiness is sickening! He just thinks he can do whatever he wants and he is always correct. Breaking in other's home and acts like it is nothing wrong?? Randomly assault people around his older brother and feel proud of it? One minute he said he would kiss his step-older brother when he is awake, the next minute he rapes his older brother when he is drunk = = I mean wtf?? If he is not delusional I cannot think of another reason.
And his cold numb facial expression is just unbearable and hard to watch.

Besides, romance between step-brothers is still incest even not blood-related, it is unnecessary, could have better characters settings. It also incorporates negative and wrong impressions into the LGBT+ community. Also, one of the scenes is that both main characters wanted to be top and don't want to be bottom, this could be borderline funny, or it just making fun of the bottoms in gay relationships, someone could find this offensive.

The step-younger brother also has mental illness, he tries to suicide to get his older brother's attention, and even plays the video showing he rapes his brother to their father... he clearly has something wrong in his head and needs some serious help.