Let me start by offerring you my sincere sympathy. While it is true that we cannot always control the actions or attitudes of others, particularly those of an ex spouse, we can however have great influence on our children no matter what kind of negative influence they may receive from whomever they receive it , in cluding that from an ex spouse or their other parent. The key is to relate to them in a way that connects them to you. If you have a good relationship with them it will serve your cause. Connecting with children is simply a matter of winning their hearts. Not in a competition sort of way. What I mean is children are open to ideals. They embrace the concept of black and white, right and wrong. You can connect to them by teaching them these concepts in a manner that allows them the ability to choose who they wish to become. You can use examples taken from stories or movies or real life. Ask them open ended questions like why do you like or dislike this character or person? And shape their views base on their answers, Most if not all children will side with heroes rather than villians. As they experience life they will become more acute of whether or not their affiliations support what they believe in their heart is right.