It is very hard to do because you have to prove that he is actually telling the kids these things with the intent of alienating you. If you mean he is going to claim it, he has to prove you took actions to alienate him. Courts tend to be very suspicious of these charges. If it comes up, you still should consult an attorney because when one succeeds, your visitation could be severely hampered.
Disclaimer: This answer is intended for informational or educational purposes only and should not be considered legal advice nor forming any attorney-client relationship.
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