Again, with all the sympathy that your situation deserves, however this is you ex-partners actions, not the airline.
I don’t understand why you would want to travel with him. And from his POV, wouldn’t he be in breach of his court order if he did travel with you? I completely understand why he would cancel his travel - and equally don’t understand why you did not. That being said, I’m sure there’s more to the story and you’ve got a lot of other factors at play, which is understandable. I just think you had a fundamental misunderstanding of how airline bookings work.