I have been a stepmom for over 12 years and it is tough! Do the kids live with you full time? The only thing that I know is that the bio parent should be the one to control the kids. How long have you been in this situation? Mothers are very protective of their kids and sometimes they don't see it. One thing is that you and your wife needs to sit down and come up with a plan on how your family relates and what the rules are. You and your wife needs to have a united front when it comes to dealing with the kids. How old are the kids? Kids are good at putting parents against each other even non divorsed parents. They know the weak points and will use it to thier advantage. Let me know more so I can help you if I can.