To be annoyed that DP didn't bother to say he was going out?

[mintich]

Normally he's home by 630, but 830pm he texts and says "sorry had drinks with the boss. Coming home now" I had been calling him but no answer. I normally go to the gym on Thursday so missed that. I've made dinner which he's missed too. But most of all we have a 4 month old baby. If something had happened to her, I wouldn't have got hold of him til now.
Even worse he was on what's app at 715 so was put then but didn't bother to tell me! I'm fuming! Would you be annoyed?

Yes. That is incredibly rude. Do it to him sometime then explain to him how it felt.

I'd be annoyed mainly because he had clearly seen his phone and missed calls if he'd been on whatsapp at 7.15. Less important if you didn't have your baby, but with the baby in the picture he could have at least told you what he was planning.

Sounds very very odd.

It's rude op , he should've let you know.

It's just very very rude. Especially considering he knew you had plans, why do his trump yours?

There would be absolute hell to pay if this were my husband! Our arrangement is very clear - outside of working hours, the twins are our joint responsibility. Neither of us would ever leave the other one to deal with it alone without discussing it first. When they were 4 months old, he had to go to London for work - normally it would have meant an overnight stay but instead he arranged to do it in one day and even then we discussed it because it would mean a longer day with them without his help. I get it's different with one baby but I would still be furious that he didn't think it necessary to tell me.

YANBU
He was rude and thoughtless

Are you me? My husband does this all the time it drives me mad. I just plan my evening around myself and my dd now, i.e cook our dinner for 7:30 and if he's home by then fine and if not he can heat it up later. He would always answer the phone though, I'd definitely be angry about that especially as your baby is so young.

Yes I would be annoyed. It takes ten seconds to send a text saying what was going on which he could have done at the start. He should also have asked if you were OK missing the gym for him to stay out. But not even letting you know till afterwards is crap.

I'm assuming he didn't want to take the chance that you would ask him to come home if he told you his plans.
He ensured that he could go out drinking by ignoring your calls.
He couldn't have accessed whatsapp on his phone without seeing the missed calls. What if something was wrong and he ignored you?

I know, it is rude! It's not like him to do that. He just text from the train home saying "I'm sorry you're mad at me xxx" I'm sure he is sorry I'm mad at him!!!! I haven't even eaten!

What made for this said, absolutely.
Really though, I think the "might have needed to get hold of him urgently if something happened to the baby" is a bit of a red herring for me, personally.
There are plenty of times when I'm justifyably unavailable at work and if there was a problem with the DCs then whoever's in charge of them has to get on with it, informing me is imprtant but not urgent.
The thing I would be pissed off with is that because you have a baby your movements (including having any free time) are significantly restricted. And if someone doesn't bother deliberately avoids telling you they're not going to be home when they say they are it's stressful, upsetting and frustrating.
His text would make me want to hurt him tbh. "Sorry you're mad at me" rather than "sorry I was a devious, inconsiderate aresehole"