My son has had a few friends like this, but the case for the only child would be the opposite. My son is an only and we hold him to a pretty high standard for manners and proper behaviours. I can't say we ever really sat down to tell him you should do this or that, we just sort of taught him by observing us. When he has had friends who are rude or misbehave a lot, he seems to lose interest in having these kids for friends.
I would scold a kid who misbehaved or was rude at my house. If the kid told his parents and they complain, no problem, your kid can stay away if he doesn't like it here.