To think ex is some sort of sociopath??

[ZubinB]

So my ex normally has our 7yo on a Monday - he picks him up from school, he stays overnight and drops him the next day. We have two kids, but the toddler sister stays with me, so 7yo gets some daddy time.
He forgot to pick him up yesterday; forgot he was having him, cut to me having to make a hasty dash to school gates with toddler sister in tow. Son cried when he realised he wouldn't be seeing his dad. (NB. Dad works from home, literally around the corner. I am a SAHM.)
He text me later with 'work really busy' but there was no apology, or visit. I said he owed 7yo an apology as he was upset. I got a 'tell him daddy works to put his dinner on the table, I don't apologise to children and mummy goes on holiday, daddy has priorities - tell him that as he cries into his dinner'
AIBU think WTAF. And if so, I what to do about it? Do I just have to continually put with this behaviour (it's not a rare occurrence)?

So he’s done this to his son lots of times? There’s not much you can do. You can stop contact - there’s a chance it would end up in protracted court proceedings with contact ordered and daddy just using it as and when he wishes - so back at square one.

He sounds resentful and bitter but don’t get the holiday thing? He shouldn’t have let your son down and you’re going to have to remain neutral and calm for his sake. If you don’t work you can be a bit more flexible when he’s a Dick, great for DS though irritating for you.
Keep an eye on how he treats DS too. One to watch.

YANBU-Tell him that: 1) An inability to apologise is a sign of WEAKNESS. He went like it but it's true; 2) Lots of parents work. He isn't a hero for that, and it's no excuse to forget to do childcare; 3) By not modelling apologising when he screws up he is failing to help his child understand social interaction and learn how to relate to others in a healthy way.

I don’t understand the holiday thing? He sounds defensive. Are you financially dependant on him? If so I think you’re going to struggle to do anything about it. Has he done it before?

He knows you’re available to pick up his slack so picking up his child is not his priority. It’s like you’re still together as far as he’s concerned. What you need to do is tell the school that his dad will pick him up on Mondays and that they therefore need to chase him when ne doesn’t turn up. You will still inevitably, end up going out but it might just embarrass him enough to turn up next time. The anger at your son is his guilt for not making the right decisions at the right time.

Without meaning to be rude, if you get a job, get out the house, put childcare in place, gain some independence, he will respect you more and be forced to do his job properly. Or, as often happens, he will withdraw and you do everything yourself but either way, it is sticking two fingers up at him and that will feel great!

He hasn't done this before, but he is often irresponsible and unreliable when it comes to the kids.
I don't rely on him per se, he just contributes his share of child maintenace - that is the money he is referring to.
Re: Holiday, I went away with friends for my milestone birthday. Paid for by my savings.

So if his contact is Monday’s, he picks up. If he forgets the school need to phone him. Then follow their usual procedures if he doesn’t show. They can’t expect you to keep picking up the slack, it’s his contact time and he is responsible for your son during it

Just text back with "Don't worry, I told him 'Daddy is a neurotic little shit who always puts himself first because he has a tiny mind that prevents him from functioning as a normal human' and we all three agreed and laughed for the rest of the evening"

Or at least enjoy thinking about doing it.