Oh my, this story is so relatable to me, yet different. With my ex, we did have an agreement that Christmas would be alternated between us but, ever desperate to make things hard, my ex would harass me each year it was my turn to let him have our son, always using the fact that I'm Jewish as a reason. Somehow, we figured it out that he would spend Christmas lunch with his dad each year, and usually Christmas morning with me. And now, suddenly, this year his dad doesn't even feel like having him, and so life changes again!