You and your children need counseling. Yiu need to go together so that all of you can learn. You are projecting your hate towards your ex and your children pick up on that. Especially the one you call, difficult. The one that is lying and not going to school but as you have stated that child never lies! I am going to tell you the truth, I'm not going to sugar coat it. Your children are telling you what they want you to hear because they experience your projection of how much you hate your ex. They are simply doing what they think You want and want to hear. Your so called "difficult child" is using you and your contempt for your ex as an excuse to get away with everything, including not going to school, and much much more. Lying is easy for that child because they know you will buy it and stick up for them no matter what because you hate your ex. That is learned behavior. 10+ years ago my husband's ex dropped their daughter off on our front porch with a tote full of clothes so she could chase man across the country. Our (collaborative our) child said so many nasty things to me, including my mommy wants to cut your neck, my mommy wants you dead, my mommy said she would cut your neck. She was five, and my husband hadn't been with his ex for years. But, she had so much hate for no reason that she projected it on her small child. She told me one time that her mommy wanted to cut all my hair off and put me in a grave! At five years old! I knew that wasn't the child making those words up, I knew it was coming directly from her mother. She is one of those people who, if I can't have them I would rather they be single, because i can't handle them being happy with someone else. She has never been happy in a relationship, she had 2 more children with a man who has a great job and treated her like gold but she still cheated on him. Made him think the 2 kids she had with him was his and guess what!!???!! But, even after all that and all the years that passed she still projects her hate towards me through her daughter who doesn't even like her anymore and wants nothing to do with her, except she is her mother. This poor child is torn. So I guess what I am trying to say is get help! You need help on the real. You need to get over your ex. He is an ex for a reason! Move the on! Get yourself a man that you can trust and live a happy life with. Then you wont project all those negative feelings towards your ex that your children lie and play your feelings about. Also, get some family counseling. It will help a lot because it will show your children you are doing the right thing and focusing on your future with them instead of spending your life hating the past and being miserable. Your child that is skipping school will love that your paying attention to them and learn that you are moving on and they need to as well. The only reason that child is lying about the step mom is because that child thinks that is what you want to hear. Until all of you as a family can move on, your child is going to make up all sorts of lies to get you on their side, which is your side in all reality. Get some family counseling. You will be amazed at all the good it can do! Trust me. I've been married for over 10 years and we weren't even married when my husband's daughter got dropped off like a puppy! We have been through counseling and we are so strong as a family now. She would never say things like that to me now, we have a wonderful relationship and she knows her mom just says the things she says because she is a bitter, awful, hate-filled human that is so spoiled they think if I can't have my ex, no one can! In all honesty that's why he left her in the first place. Dont be that person, and dont teach your children being like that is o.k. behavior! Teach them to learn a bad relationship is exactly what it is, a bad relationship! You dont have to live through it, you can move on! Everyone has the ability to move on and find the right way to live their life. Stop projecting how much you hate your ex on your children. Let them decide for themselves. If for some reason they decide they aren't compatible with their father, then oh well, but dont take their father away from them because you hate him and want everyone around you, including your children, to hate him. You can't blame your child for having a relationship with their father and it sounds like that's exactly what your doing. Keep your feelings to yourself. Let your children spend time with their father and new lady without talking about her. Let them make a decision on there own, so what if they end up liking her. Isn't that a good thing!!?? Would you prefer your children spend time with someone they hate because you taught them to hate that person or would you prefer your children to enjoy their time with the person that is just trying their hardest to make your children happy?? You need to lay off the projecting of hate and get some counseling. It will help leaps and bounds and I guarantee your so called "difficult child" will change drastically. Once you are able to move on and accept the life you have, your children will be able to as well. They will stop lying about the step mom and have a great relationship with the both of you! Co parenting isn't hard as long as both of you realize that's was the beat decision for both of you. And, like I said, your children will quit lying and be happy! They will realize that's the way things are and my parents are grown enough to have a good relationship. It means the world to children to know parents can live happily apart but still be civil.