Wow, sorry to hear this, can be devastating to children. My brother's ex became a pro at this. Not sure if you already have an attorney, Diana March is excellent and is very aggressive about parents who abuse the other parent & hurt the kids by using the kids as leverage. The devil is in the detail, you have to show & prove there is consistency with actions and manipulation by the ex that is causing harm to the kids. Are you tracking all detail, may be using a journal to show blow by blow so trends can be identified to avoid assumptions that actions by this other parent are random? How are the kids doing in school? Is visitation with you to the letter of the decree or shortened because other parent changes drop off, pick up, arrives late, shows up early to pick up, etc.?