Oh, it's heartbreaking sometimes isn't it? My DD has had the same problems throughout primary school & there have been times when I've cried tears of frustration in front of her teachers. My advice would be to keep communication open with the teacher because they may not be aware that there is a problem. Also, if your son has been the instigator then it is easier to deal with if the teacher feels that you are approachable & isn't going to bite their head off. Eventually I took my DD to counselling to help her build confidence & teach her to interact with other kids in a non aggressive form. Good luck & big hugs xxx