I ended up hurrying DS out the door a bit, thinking that he needed to go spend some time with Dad so he could get back at a decent hour and play for awhile before bed.  I promised him he could play when he came home.  Now, I had given Ex the option of keeping him until Wednesday afternoon when he goes to work and taking him to Fiance's house (I am working, Fiance is off today) or bringing him home before bedtime Christmas night.  He chose to bring him back Christmas night.  So he said.

Last night 8:30 rolled around and no phone call.  We started texting Ex.  He says that he is going to being him back Wednesday afternoon.  Trying VERY hard to be Zen, I asked if he wanted directions to my Fiance's.  He called.  I calmly explained to him that I found it rude that he decided to change the plans abruptly without discussing it with me, and that I wanted to avoid future miscommunications.  Then I talked to my mom.

Apparently, he called them at 6:30 while they were driving to my sisters house 5 hours away.  At that time, he said that DS had been "driving him crazy all day wanting to go home and play with his toys" and that he was now asleep and that Ex was going to call me and ask if he could stay the night.  That call never came, obviously.  My mom also told me how she and my father are upset about Ex saying to them recently, in a spiteful tone, that he hoped I realized that next year he would have DS for the whole Christmas holiday and I wouldn't get him at all.  I burst into tears. (Note: The custody arrangement says that each parent gets him every other holiday, but doesn't give specific times or dates)

My parents keep DS every day while I am working during the days I have custody, and the evenings while Ex is working during his custody time.  I am the primary custodian.  Ex ends up leaving DS there almost every weekend he has him, claiming work.  My parents are wonderful, loving people who still do things for Ex like help him fix his car, loan him tools, and got him several Christmas gifts.  He didn't get them so much as a thank you card.  But that's not all that shocking, since my mom told me that he didn't get his son anything.  Not a single Christmas present.  Said he "didn't have the money".  Which is BS.  He makes plenty, he just didn't think about/prioritize buying DS a gift.  So no wonder DS was so upset over there.  My fiance was so upset by this that he wants to tell my parents that if Ex ever says that again, they should tell him and he will give Ex money for gifts, so that DS doesn't have to go through that. I don't even know what to think about it.  It's despicable that Ex acted that way.  Taking DS away from his extended family, toys, and special dinner, to be alone in a house with no toys (he hardly keeps anything there for him), no family and no special food.

But it gets better.  Ex's family celebrates Christmas over New Year's weekend.  Which happens to be my weekend for custody.  Once in mid November, when we were working out Christmas day, he mentioned that to me in passing.  He hasn't said a word since.  He keeps telling my parents how he is going to be taking him down there on Saturday and coming back on Tuesday.  When he dropped DS off today he said "See you Saturday" and ran off before Fiance could say anything about it.  But not once has he spoken to me about the logistics of this, asking if he can have him this weekend, or what time he can pick him up.  He has had every opportunity, and obviously just doesn't plan on doing it.  I can only imagine that he just thinks he will call on Saturday morning and say he is on his way.

So I am in the uncomfortable position of on one hand wanting DS to have the chance to go (even if Ex's family treat both DS and I like crap, they are his family and he loves his cousins), and on the other hand, I need to set boundaries with the Ex and let him know that this is not okay.  He cannot do this, just randomly taking him whenever he wants (and dumping him off when he wants).  I want to do what's best for my son.  And I have been trying so incredibly hard to be nice to my Ex and work everything out for the sake of my son.  But he refuses to work with me, even a little bit.  So I don't know what to do.  Let him go or cause a huge fight because of the principle of the matter.  If I don't let him go, Ex will act even more childish and mean.  If I do, I am essentially telling Ex that he doesn't have to play nice, or be respectful or courteous, or do what's best for DS.  I will likely lose any chance of working out amicable arrangements so I can see DS next Christmas (although apparently Ex is planning to keep him from me anyway).  To top it all off, I really need to spend time moving next weekend, so it wouldn't be horrible if DS wasn't there, but then Ex will have him 3 weekends in a row.

I am incredibly upset by this whole situation and have absolutely NO IDEA what to do at this point.  I just don't understand why, when I have bent over backwards to be nice and to make this all work, he can't just have common courtesy.  

Has anyone else ever been in a similar situation?  Any sage advice for me?  What would YOU do?