KerantliDreamer

It's easy to see why people think Ron's a jerk. He's insecure and often insensitive. There is a tendency for fanfic writers to go way overboard with that aspect to him to justify Hermione being paired elsewhere. In your case you had him start in about Hermione about being muggleborn something in canon he would never ever do and has never displayed much in the way of anti-muggle opinion. (the worst i think was arguing with dean about football of all things)

I have since actually tried to explain his actions, and will be explaining that more in the next chapter as well.

He can be a jerk in the books, as well as jealous (GoF) which tends to set off his infamous weasley temper