Until last week my ex has been living with me to help with kids during lockdowns etc just made it much easier for all of us and it worked well, we get on well (usually!) He moved back out last week and we arranged days and times he would see the kids (has to be at my house, where he lives isn't suitable as he rents a room). He messaged this morning telling me he would be coming 2 hours later than arranged, his reason was not a big deal or urgent and could easily have been arranged for another time (a friend was coming to pick something up from him).
The issue here is that this happens all the time, it isn't a one off. Before he had come to stay this happened almost every weekend and we had so many arguments about it, he never asks if it's OK he simply tells me which pisses me off. He doesn't care if I have other plans, even before covid when we actually could make plans. I think he is being incredibly selfish but he doesn't seem to see it from my point of view.
I have no choice but to go with whatever he does, what else can I do? I can't make him come on time, I don't want to stop him coming at all as it is the only break I get (we have DTs who are 3 so you can imagine) and the kids adore him.
I can understand needing some flexibility but this is something else entirely, he expects me to pick up the slack without question. AIBU to be annoyed about this?