To have left DP for the day with no warning?

[WomanEmpire]

I'm currently studying, have 2 small DC and do most of the housework/childcare etc.
DP works 40 hour weeks. He had Saturday, Sunday and today off. He went to a stag do Saturday afternoon and return early Sunday afternoon.
He was hungover and tired and not being very productive, that was okay. It's a Sunday we basically just ate, bathed and all went to bed.
Today when I got up at 7 to get DC1 ready for school, DP was snappy because he was exhausted and I was reluctant to take DC2, whilst he slept until we left.
It really bugged me and I've got a shit tonne of work to complete before the week is out. So I took dc1 to school and text DP saying 'I'm going to pop in on Friend, have a tea and do some work in a cafe, that alright?' And he didn't reply so anyhoo, I did exactly that. Managed to actually complete some work, collected DC1 and came home.
The house was awful, I'm not a tidy freak in any stretch of the imagination but it was like a bomb had hit. Apparently he 'feels I was unfair to expect him to take DS2 on his day off with no regard for his plans' I did say, 'are you going to sort the kitchen after dinner?' To which he said, 'yeah when I'm ready' but to be honest, I had to wash up and clean the sides to be able to do dinner anyway.
I don't know why he upset me so much, but I just came outside and sat on the doorstep and had a little cry. He came out and apologised but added 'I wish you'd just given me a heads up that you were gonna be out all day'
So, WIBU?

unfair to expect him to take DS2 on his day off

This makes me raging fucking angry on your behalf!! How fucking dare he! This is HIS CHILD. His own child. His own responsibility. What fucking rule book on parenting did he read that says he gets to decide when he does and doesn't need to parent his children?!

Of course you weren't BU. I bloody hope you didn't apologise. Well done for getting some work done.

Obviously, ideally you'd both make prior arrangements together. But it doesn't sound like he'd prior discussed with you his plans for totally opting out of parenting today.

What you did sounds fair enough to me. A 'day off' means not having to go to work, not 'no-one can ask me to do anything, ever'. On my days off I expect to be doing stuff with DCs.

sounds like you need to do it more often

He does realise that "day off" in this situation means, "day off from work" not "day off from family life", right?