It’s 1 day.
I’m sure it was not a fun day for him, he’s probably very stressed about the prospect of his parents splitting up, so not selfish. However they are adults and it’s ridiculous to think he can play any role in their relationship so there’s really no point in him being there unless he’s helping one of them move out or something
He’s an adult, it’s his parents and they’re on about divorce. This must be huge for him. I think I’d be silently annoyed. If he says he’s going round there again just casually ask, do you know time roughly you’ll be back? Could you not have leaned on someone from your family for support for the day?
They shouldn’t be using their son for help
He’s got a 4 week old baby at home??? No you’re not selfish… his parents need to put on their big kid pants.
What exactly has your partner been trying to sort out? 🤔 I mean if his parents have been having issues to the point where cheating and divorce are involved, first of all as parents, why would you want your adult son privy to details of your sex life (extra marital or otherwise)? Second of all, he’s not a third party to their marriage so why is his input needed anyway? Yes he is their “child” so to speak, but they are a grown married couple. Nothing he can say or do will make them stay together. It’s not like he’s a small kid and will factor into their decision to stay together “for the kids”. Yes it’s sad to find your parents may be divorcing when you’re an adult, but to spend 12+ hours with them over it, sorry but it sounds like a cop out and more likely he wanted a bit of alone time given you’ve got a newborn and toddler. How do you know he didn’t spend half an hour with them and then the rest of the time at the pub or just watching TV/gaming in another room?
My kids are the same age and I feel for you, I'd be drowning. But thats his parents and they're in crisis. Maybe this is something you can talk to him about, having an expectation or a limit for how long you can tolerate being alone with the kids without support.