It turns out that ds is being told not to play with other friends,to not take part in various activities he usually does at play time, to eat exactly the same thing as bf.....otherwise he will not be ds's friend or let him come to his house. I am friends with the boy's mum so it is rather awkward but obviously I have to put ds first. We had a chat with ds and he understands that what bf is doing is wrong. We advised him to stand up to bf if said behaviour continues and to tell him he doesn't want to go to his house if that is being used as a threat. We also advised ds to tell the teacher if it continues. The boy in question has been struggling at school recently (another reason why it will be difficult to raise topic with his mum)- not wanting to go and clinging to parents. I wonder whether he is trying to control ds because he feels so out of control iyswim. Ds has been very supportive of him during this time and because he feels bf is delicate, is worried standing up to him will make him upset. This morning the TA approached me to comment on ds reading so I took the opportunity to mention it, saying I wanted to keep it low key at the moment but just wanted them to be aware. If this was your dc, how would you handle it?