While I would be upset if my son was not polite, I wish he wouldn't play with a naughty child! His friends now are nice, polite children but we did have a huge problem with a naughty boy before that staff would not tackle - me and his best mate's mum were so cross and fed up of bad behaviour trickling home and them blaming our sons for this other boy's actions we moved nursery school.

I also do this at home - if DS is deliberately naughty, I won't play with him until he apologises or clears up his mess. I think it's fine to not like naughty people!