Gving definite bounmdaries isn't being mean, it makes kids feel safe and loved. It sounds like the lad is looking for his boundaries, testing to see how far he can go.
Your bf should follow the rules set by the boy's mother, for things like table manners etc. Also, he is not too young to realise that slightly different rules apply in different houses - eg in some houses it is customary to leave shoes at the door, while in others shoes indoors are fine if they are clean.
The best way to win respect is to give it, for example thanking him for correct behaviour, not just scolding him for bad. It's easy to get annoyed when someone is making a noise while you are on the phone, but try thanking him for keeping quiet while you're on the phone (again just an example). He should find he doesn't need to play up to get attention if he gets attention anyway.
Honestly., it works!