I have a 13 year old son who contantly teases his younger brother, does not do his chores, does thing that he knows are wrong. When you speak to him over something he has done wrong he has this smirk on his face,like he knew what he was doing and he could care less about what you have to say. You can ground him from going out or items and it doesnt phase him. He is argumentative. He puts off everything he two siblings do everything they are suppose to and follow all the rules.
This is a constant thing. My husband and I are pulling our hair out. We have run out of ideas. He is disruptive to everyone in this house