I can't remember what we did on Christmas, but I think we alternated years, either having SS overnight on Christmas Eve and then he went back to BM at 10 am, or we were the ones to get him at 10 am on Xmas day.  I am in the US, so Boxing Day had no real significance as a holiday.

Seems to me you had the kids from Christmas Eve to 11 am Christmas morning, which for me anyway, is the bulk of the "important time".  While he should of course have followed the agreement and had them back by 11 am today, I'm a bit confused on how you "weren't with your kids" on Christmas when you had them until 11 am?

Sounds like he's a jerk, but if you have them 90% of the time, is this a real hardship? Also, stop sending him pictures of the kids, unless you feel it's good for them - if he's not going to reciprocate, you can stop doing it too.

Maybe I'm missing something.

For many years, BM came over to DH's dad's house and they would all celebrate together. That stopped when DH and I moved in together, at which point BM and DH worked out trading Christmas Eve and Christmas Day. BM wanted them for Christmas Eve for church and Christmas morning, then DH would get them Christmas afternoon (and usually the following week for the second half of their Christmas break). This year, BM seemingly forgot she had kids (who are now a teen and young adult) because she forgot to tell them when and where to meet her for Christmas until after dinner (and after she spent the day celebrating with her new BF and his family).

Regarding your situation, where you have someone trying to be controlling, there are three ways you can approach it. First would be to file contempt charges against him for being late with drop-off. This will likely escalate his controlling behavior, so not my favorite option, but an option. Second option would be to go pick up the kids, or switching to where the kids are picked up by the parent who is taking custody time. Sure, he could come early, but then you just wait until it's his time and then release the kids to him. Third, and my personal favorite option, celebrate Christmas when you have the kids whether it's Christmas Day or another day. That gives your ex no control because you'll reach a headspace where the day doesn't matter, just your time with the kids. And your ex can't take that away.

I hope you have a better today than yesterday. Best of luck!

The fact that exH spends less time throughout the year means the time he does spend matters even more.  It is in your children's best interests to have the best relationship with him as possible. 

Your kids have two parents and he is one of them.  You and everyone else will be happier if you accept that their time with him is important.  Lower your expectations and be flexible.  Many parents split Winter Break in two parts late in the evening Christmas eve, alternating the first and second parts.  Celebrate when you have them, and know they are having a good time when they are with him.  Offer him a fair schedule.  Maybe a bit of goodwill and a polite request would get you the pictures you want. 

Later in life you will have to negotiate a schedule involving exH, your kids' work schedules, and their SOs' families.  Flexibility and reasonable expectations will make it all so much more relaxing for you.  

Firstly, he should have followed the agreement and should have let you know if he was going to be late, so I'm not marginalizing that.

I think in situations like this, nothing will seem "fair" unless it somehow worked out that you wanted Christmas Eve and he wanted Christmas Day. If you both want the same time, then you need to alternate in some way, which will cause heartache for whichever parent doesn't have the kids during that time. In our case, BM demanded Christmas Eve and gave DH Christmas Day starting at 10am, but then DH's family refused to move their celebration from Christmas Eve, so DH would have to drive skids around to see people who weren't actually having Christmas and that made Christmas miserable for him, so at a mediation two years ago, he pushed for alternating (in return for more money for BM). BM gladly signed the agreement to get the additional money, but then decided it wasn't "fair" for her not to have Christmas Eve and harassed DH about it almost immediately after signing the agreement. Now, BM has a new boyfriend who celebrates Christmas Day, so this year (her Christmas), she was happy to take both days. Next year, when it's DH's Christmas, I'm sure she'll harass him again, but everyone was fine and skids had a great time last year celebrating Christmas Eve with DH's family, so she has less ammunition. All that is a very long-winded way of saying that if you both want to celebrate at the same times over the Christmas holiday, you will always be disappointed and your only option is to find other things to do when your kids aren't around. 
 

Regarding your ex sending you pictures of Christmas, you need to adjust your expectations. Don't expect him to do what you might do. If you want to keep sending him pictures and can do that without expectation of anything in return, then continue to send them. If not, protect yourself and stop sending things to your ex. 

It stinks to not be with your kids on a holiday, but unfortunately, in a divorce situation, it's a reality you have to accept. 

Regarding the controlling piece, you need to learn to pick your battles. My DH is super passed and MIL is super controlling and manipulative, so he would just do whatever BM wanted. When I met him, she told him when he would take his time over the summer, she would not come back on Sunday in time for drop off, so he would take time off from work to keep skids and take them to school. She would plan things on his weekends with skids and demand he take them (never asking if he had things planned). She would dictate what they could and could not do on his weekends. It used to drive me crazy. Pushing back on her usually just unleashed a torrent of vitriol. We learned to prioritize what specifically we wanted and we had to let a lot of things go. We also moved to limit contact. When you're dealing with a high conflict or controlling person, you need to set strong boundaries and stick to them.

I don't know how your court order is set up if it is alternate chirstmases with each parent or he gets them all. Either way when your kids are not at your house on christmas day I would choose another day near christmas when you have a whole day with the children that you start a new celebration that can be either christmas with mom or a separate celebration that has traditions special to you all. 

Then perhaps just have low key plans for christmas day when they are at their dad's. Maybe frozen pizza or something easy for dinner that the kids will enjoy and watching movies in pjs with popcorn or something. That way the plans can be pushed to whenever the kids show up and take little preparation.

Alternatively maybe see about just giving your ex the whole day so you can celebrate with your friends or family and are not waiting on the ex. If you have your own celebration another day with your kids then it might not feel like such a loss. 

Christmas is a special day but there are many who celebrate on days other than 25th december for a variety of reasons. Your kids will still remember spending fun christmas' with you even if you celebrate on a different day. 

The fair thing is to have the parents alternate holidays.  So one year, you have Xmas eve and Xmas morning.. he would have Xmas Afternoon and Boxing Day Morning and the next would be flipped.  Just because he doesn't have them that much during the balance of the year.. isn't necessarily a reason to want to withold time from him on Christmas.

Ideally, you have a CO that lays out custody.  I'm not sure what is causing his lack of visitation the rest of the year?  Is it your choice? His?  His job? Distance?  But, when you have those kids 90% of the time, it seems to be a bit mean to use that as the reason why he shouldn't have any time with them during Christmas.

And.. yes.. he should have had the kids back on time... or had a good reason and communicated that to you so that you were aware of a possible change.  You could have also made your own arrangements to go pick the kids up from him when they didn't show up at 11.

I also assume the kids have a long break from school during this time, so if you have them most of the time, there are plenty of other days that can be made special.

The reality is that when you have kids and don't stay together.. there will be accomodations and compromises that everyone makes.  You can turn those into a positive for the kids.. getting TWO christmas days.. etc.. But, barring abuse or neglect your kids lives will be enriched by having a relationship with both parents.  

And.. while you may have sent him pictures in the past.. there is no obligation for either of you to document things for the other parent.  He is entitled to have a private Christmas with his kids.. and you are entitled to the same.  

In the end... how late did he end up being and did he give any apology or excuse?

And.. I understand he was supposed to have a time line.. and that he didn't follow that... but depending on how long it was.. and what impact it really had on your plans... was it an annoyance.. or was it a complete disruption where you missed planned flights or something.  Try to put it in perspective and don't let it ruin the holiday for your kids.

If this isn't a crew, then holy golden uterus.

She has them 90pct of the time and she is mad he has them two hours past a 24hr holiday?  Sorry, but that is horrificly entitled and wrong.  I'd bet anything SHE is the controlling one.  

That sounds rough and not fair. I usually keep my kids on XMAs and have a similar custody with their dad as you (it sounds like). It's not fair that they do barely anything all year and get all the fun holiday time. I get it for sure but my new perspective has been, who cares, it's just a day and we can pick another day before or after to do our XMAs our way. Plus it's good for them to have time with their dad too even if it is unfair. I think they will realize when they get older who really did everything and sacrificed for them. Try to do something calming and nice for yourself next time? I find it soothing to take a nice "me" day on certain holidays when I am alone and go walk, shop, or eat something my kids would hate (health food) lol

To add, we also never send pictures and I allow him to have his time just like he allows me to have my time. He may not care but I think the provacy in a way is good for the kids so they don't feel the pressure and can just be with that side of the family not worried about if I will be upset about whatever comes up...

The best way to let him not control the narrative.. is if you decide to alternate this major holliday.. and I mean the "whole holiday."  Christmas Eve through Boxing day.  One parent gets ALL of it one year.. the other the next.  If they want to take a winter holiday with the kids.. it makes it easier to do that.  It also means that people don't have to do the shuttling on their holiday.

So, you give up total control to him one year.. you get total control the next year.

If he chooses to not exercise his full 2 days..then bonus for you if you want the time... but you each get a full opportunity to enjoy the holiday without interferance from the other parent.  The years you don't have the kids? do Xmas before or after.  kids will appreciate the gifts whenever..lol.