years ago I was in a similar situation what ever I did or say I was always the outsider , I tried my best for a long time both time and money till I realised things would always be like this and to save a lifetime of crap I walked for my own sanity
Oh Dear

. . . I think he needs the man 2 man talk down the pub. If that fails there's always the threat of physical violence, :evil just make sure your M8 denies all knowledge of any such conversation taking place. :rolleyes I.e. make sure there are no witnesses.
Treat everything in life the way a dog would- if you can't eat it or foc it, forget it.