**um,I 'thought' I was responding to a question about children picking on your son, as previously posted??? I guess you 'revised' that and re-wrote another question?
Sorry, my response below may not apply now.
I STRONGLY recommend that you tell the Teacher. It can possibly escalate.
I have a 5 year old... and in both preschool and in kindergarten, and now in her first grade class.... there has always been MEAN kids.... .either in the class or in direct interference with my own child. Once a boy, a known trouble maker, spit in my daughter's face and made fun of her; once a boy hit another boy in the crotch during recess; once a bunch of girls (habitually) teased & excluded and bossed around another girl... in these cases, my girl told me about it after-school. I told the Teacher. The Teacher was very grateful I told her. Even teachers do not have eyes in the back of their heads... and they cannot possibly "know" and "see" EVERYTHING that happens. So to me, this helps them by telling them.
In ALL situations, I told the teacher. In ALL situations, at each grade my daughter was in, the Teacher's have all told me they APPRECIATE getting head's up about it by the Parent.
ALL the teachers my daughter had/has... they have ALL corrected the situation both directly with the child or children involved AND ALSO talking to the WHOLE classroom about it and how being "mean" is NOT TOLERATED at all.
Understand, that children like this, are already "bullies." And your child is getting bullied. If it does not stop... in the succeeding grades... these perpetrators will BULLY other children as well.
In my daughter's school they have a "No Bullying/Harassment" Policy. In my daughter's class... children like this are (1) sent to the Principal's office (2) The Parents are called in and telephoned about it (3) the children are given time-out or some kind of privilege taken away etc. or suspension if it is chronic or endangering to other children etc.
YES is it "cruelty" as you say. Yes, kids need to learn about life and the good and bad. Yes, they can "shake it off" and ignore the Bullies.... BUT OUR CHILDREN ALSO HAVE TO LEARN ABOUT PROBLEM SOLVING & THAT THERE ARE PROPER WAYS TO DEAL WITH THESE PROBLEMS. ie: that the Parent will tell the Teacher... and for our children to "see" how things like this are handled. I strongly believe in this.
My Hubby & I ALSO teach our girl, that whenever anything "mean" or bad happens to her, she must tell the teacher, or the Adult in charge. They must be taught this. Taught problem solving and not just "sucking it up" and putting up with mean behavior.
NO child should have to put up with bullying, or these kind of mean behavior.
Tell the Teacher.... it is not just about teaching your son tolerance and moving onto another "friend." It is also about TEACHING our child, what is mean and what is not, AND that something can be done about it, that NO CHILD should have to be a victim and be 'quiet' about it... all this does is enable the bullies and allows them to keep doing it. Bullies learn very quickly who will turn them in, and who won't.
I also feel, that by telling the Teacher.. .that this also helps the child involved (whether or not it is 'your' child), because not all children will 'tell' their Parent's what happens to them at school, not to mention the 'bad' stuff too. And, not all Parents will act or do something about it to aide their child. So for those children, I feel it helps them too. And, might I add... if you are not comfortable about "telling" the Teacher... you can just mention that you want it "anonymous" and the perpetrator's Parents don't "have to" know.
Yes, kids this age can be mean. Heck, even when my girl was in Preschool....at 4 years old, there were mean kids there already.
Take care,
Susan