It's a friend of a friend really, but he's talked to me about about it because I've done some work with troubled teens.
This child's behaviour is extreme. I'd say there's almost certainly been significant trauma. At work I've never seen behaviour like this unless there is. I've no idea what that might be and I'm not going to ask, suspect father might not know.
However, two things I've observed, which won't be helping are:
- step mother clearly doesn't want the boy in the house, doesn't want him on holiday with them them, can barely be civil to him. I don't blame her, he's done some awful things, but if he wants to help/support his son, father can't put up with that and should, IMO, remove them both from the situation.
- Father's response is very negative. For example the boy does very well at sport. I said how impressed I was and asked about his training. Rather than yes, he's doing very well, Dad said "he's lazy and could be so much better".
I don't know if I should point out these things won't be helping. I was asked (kind of, very informally) but don't have anything like enough information to help them properly and wouldn't attempt to anyway, but some friendly advice, that they asked for but won't won't to hear, or keep well out of it?