You do not need to worry. I am thirteen and I had the same problems when I was younger. I admit that I had very severe anger issues, and am quite embarrassed about it now. What you need to do is lay off of him a little bit. I know that it’s your parental instinct to help your kid when he has bad grades, but constant reminders and badgering usually causes these bad mindsets. I know because of my father. I really do relate to my mother and don’t like working with my father. This isn’t because of anything wrong with me, but it’s what’s wrong with the parent. My father is very nosy, hypocritical, grudge-holding, egocentric, and the likes. Long story short, he’s not happy unless you admit that he’s right, and always right. You should talk to your kid about this. If you’re the one he won’t work with, there’s no need to worry. You don’t at all sound like the person who’d act like my father. But still, you should talk to your kid and, if applicable, to the parent he won’t work with. You need to know what both of them think to figure out accurately what’s going on between them. Good luck.