I fully endorse both of these replies. Very sensible and constructive. I wonder how the child behaves with his own mother? If he is just as unruly with her, don't despair; it is possible for children's behaviour to be modified, according to the people they are with. If you remain calm but firm and, very importantly, you accentuate the positive with lots of praise, even for the smallest of good behaviour, you will win this child round. I understand how resentment can easily take you over when there is someone nearby who just doesn't lend a hand or support. Try finding opportunities of being alone with the child, giving you the chance to instil your own set of values and indeed, build a close relationship with him. Keep calm and good luck! Let us know how you get on. A regular progress report could well encourage you.