Tbh I can kind of relate to him and how quick he changed his attitude. I wasn't the best daughter to my mother; but not as bad as him though. I didn't notice it when she suffered or how to comfort her. I was sometimes annoyed that I wasn't allowed to do some stuff with my friends. But now that she's gone, looking back I wish I have the same chance as this guy. I would do everything just to make her happy and I would love to do many things with her, just like what he's doing to his mother.
Ps. I don't see any incest happening. Its just him worrying/wondering who the guy his mother is seeing. Since his previous dad was an jerk and just wants his mom to be happy.