In a recent case of a family with a history of violence and drug and alcohol misuse, where the parents live thousands of kilometres from each other, the judge ordered that the children live with the mother and spend holidays with the father (among other orders). The judge said: “I have serious concerns about the mother’s willingness and capacity to encourage and support a relationship between the children and their father. The mother should be aware that if her obstruction and unwillingness to facilitate a relationship between the children and their father continues a court might reach the conclusion urged by the independent children’s lawyer that the children would be better off living with their father.”
Children have a right to a meaningful relationship with both parents and each parent must support that relationship. Bad mouthing or saying bad things about the other parent to the children in order to drive a wedge between the children and the other parent is not supporting the children’s relationship with the other parent.
You don’t have to like your ex, but that person is your childrens’ parent and children grow up happier if they have good relationships with both parents.