I really liked this story at first. but I'm afraid it's become more and more difficult for me to suspend my disbelief.
First of all, the reader is supposed to believe that abuse this common is not being noticed by anyone around Spencer? Where are the teachers? He's a genius, surely one of them would take notice if he kept coming to class with black eyes. Especially since the whole school apparently stops to witness the latest ways Riley and Dexter torment him. Does no one teach or patrol near the area they beat him up? Also, how has he not required medical attention for any of his injuries? He seems to be good as new fairly soon after all of his beatings, even in this latest chapter.
Secondly, Spencer works at a hospital. No one there intervenes or notices the signs of abuse? You've mentioned Nix's mom noticed something was wrong with him, but she never follows up on that? I'd not have a problem with that, but adults outside of his own family seem to like Spencer. They'd have every reason to want to intervene if they suspected something was wrong.
My biggest complaint though is that apparently everyone has forgotten that Spencer saved Nix's life. I don't know, you'd figure that would earn him some gratitude, at the very least from Nix himself. But everyone seems to be grateful to him for one or two chapters then forget all about it. The friends that care about Nix's wellbeing so much are right back to beating up the person who just saved their friend's life. And Nix lets them, convinced of the evilness of the person who again, just saved him. That alone says all that needs to be said about the utter vileness of almost every character in this story.
The story's not badly written. But increasingly, I find it difficult to read it as anything other then "How will Spencer be tortured this week?'. Bullying is a very real probelm,and it's important to touch on. But I feel like this story takes said abuse up to eleven. Now apparently Artie and his friends are going to find a way to scar Spencer in yet another way. I think I'd complain less if the abuse had any notable effects on him. But so far he does not seem bitter, or even all that angry. I don't remember him once voicing suicidial thoughts or homicidal, for that matter. He seems very much like a saint, and given the abuse he's endured, I find that difficult to believe.
You said you wanted to create a realistic story. As it stands right now, I'm sorry to say that you were not successful.