Hello,
Ive been having trouble with my 13 year old behaviour for a while now, and last year after arguing with ds, he said one of his friends held his hand behind his back and pushed him up against a locker. I spoke to school and they said they will keep an eye on him.
This friend has autism and i spoke to ex about ds behaviour and mention ds friends behaviour and i said i was worried about this friends behaviour with ds. Ex just said its normal teen behaviour and ex has a child that has autism and questioned that i dont like ds friend as just because hes got autism 
Fast forward to yesterday, my children know i may look at their phones occasionally, so i was looking through ds' phone when he was in bed and i found a msg between ds and this friend. And ds told him that hes pinching him and he has to stop or ds will tell a teacher, and his friend replied that snitches get stitches, and that his dad hurts him and he needs to release it.and thats just how he is, so if ds dont like it he not excepting him for who he is and if he dont like it they wont be friends anymore 
I havent spoke to my ds yet that i know about the msg, but i dont know what to do for the best cause i dont want to speak to school and nothings got done, i feel like ive just thrown my ds into a firepit.
I really want to help my ds and we have had conversations before about IF people "friends" behaviour is like that then they are not real friends, but ds said they are together in nearly all lessons he has with this kid and ds does actually want to be his friend and in the past he said the last thing was the only thing that has happened. DS told me his dad said its normal behaviour and this is what my ds hates about me is that im too over protective !
How do i approach this please?