I hope this isn't too confusing to follow:
There are 3 preschool boys, lets call them X, Y and Z. X and Y are friends, Z wants to join in and play with X and Y, but X won't let him. X is worried that Z is going to take Y away from him. Now X has started picking on Z when he thinks no one is looking. This morning I saw X grab Z and hurt him, and he was very intimidating. Z is a quiet, shy boy and says nothing, just withdraws into himself. Z has been having trouble with anxiety and not wanting to go to school and I'm worried that the way X has been treating him is contributing to this. I was watching them this morning and X kept coming up to Z and doing little acts of aggression, being out and out mean, and sneaky. Z got quieter and quieter and more and more clingy. Z's mother was there but did not see any of the incidents.
I really feel concerned for Z. He's not very verbal, and won't speak up if he gets hurt. All he did this morning was say hello, and for that X started on him. These kids are only preschool age, so they all have a lot of growing up to do and I don't want to label X as an aggressive child because he's so young but I am worried that there's the start of bullying happening here. These kids will be at school together for many years and I am worried about Z who is a very sweet, intelligent little boy but not as physically mature as X and an easy target.
I spoke to the teachers and told them what I saw, and that I've been concerned for a while due to things DS has been telling me. I also told X's mother (that was a difficult conversation, but we are friendly and I thought she needed to know. She was shocked, but quickly said it was all Z's fault. :-( ). Would you mention it to Z's mother too so she can keep an eye out or leave it to the teachers to handle now?