[quote sillysmiles]@Interrobanger but equally the OP hasn't said anything about his reaction to the kids making noise or messy play. It reads as though she is anxious and jumping through hoops, but has not mentioned anywhere (unless I've missed it) that he has reacted negatively to anything.
I'm not saying your wrong, but to me, this all seems to be coming from the OP rather than her DH.[/quote]
Yes, that's how it reads to me too.
The stuff about him coming to see what's going on if a tantrum is happening doesn't seem of itself unreasonable - I can see that many parents would be more upset if the working parent completely ignored them at those times when actually the parent caring for the kids needed a hand.
This sounds like it's becoming much harder work than it needs to be.
Anyone WFH really needs a designated space, especially if there are others in the house at the same time. My employers insist that if you WFH, you are in a room with a door which is not used by other household members at the time, because a lot of information we have is sensitive/ personal. So you can work from your kitchen if you're home alone 9-5, if you're not, then you need a bedroom or other room to work from.
That said, you say he has an office, so a designated working space. With the door closed, unless you and your DC are ridiculously noisy or he is very noise sensitive, he shouldn't be disturbed by the noise.
If he emerges from his office during the day (and tbh he needs not to be sat in the same place for 8 hours, he'll get a DVT!) then it's fine to come and say hi and then go back to work. Your children can be told that daddy is working; and if they start to get upset, just distract them with something else once he has to return back upstairs.
Is he actually complaining they are too noisy? Or are you projecting this, and creating a problem where none really exists?
I also don't get the 'dying inside' comment - if this was me when my DC were small, surely you'd just respond with a 'kids, what can you do' shrug. they're his kids as well, and again doesn't necessarily sound like he's criticising your parenting, he's just saying he could hear them.