D.A.
This is a very difficult situation to be in. You can avoid the "whatever, I don't remember" response by writing down a behavior contract which he, you, and your husband sign. He agrees to the rules of the house. In return, you agree to give him something he wants - TV or computer time, choice of dinner one night a week, a favorite activity. He loses privileges as he misbehaves. Negotiate, and give on the minor issues. Don't get upset; just calmly enforce the rules. Tell him how he behaves at his mother's is between her and him, but you are responsible for how he behaves under your watch, that you want the best for him. Build relationship, and try to get past the "evil side." This is a little kid whose mom is acting like a two-year-old. Try to rise above that.