my ds (4) has a younger friend (3) who is very aggressive. When I've been around him and his mum, she has acted very passively with him, even when he is being aggressive with other kids. In the past, I gave them a lift home and the friend punched my ds in the nose and gave him a nose bleed but his mother barely said anything. Anyway, my ds went for a playdate at theirs yesterday and last night mentioned the friend had bitten him 3 times - sure enough, there were bite marks on his arm and leg. I would find it difficult to say something to his mother but my ds is in montessori with this child and a group of the kids play together a lot at weekends and so on.....aibu to let it go or is it better for everyone if I try and have a chat with the mum?