DP has recently moved in with me.
Yesterday, we were supposed to go to this restaurant for dinner. This is the kind of restaurant that requires you to make a reservation way in advance and we've been looking forward to yesterday night for weeks.
On Fri, DP's sister called asking him if he could look after his nephews (aged 10 and 8) from "tomorrow afternoon onwards" because her and her husband have had a stressful week and would like to take some downtime to have dinner + movie together. DP agreed!!
This caused an argument and I ended up going to the restaurant with a friend of mine. Came home last night and DP was sulking. He's upset that I went without him, that I wouldn't compromise and go get a pizza with him and his nephews instead, that he was left alone to run around after his nephews who are very loud, full-on, and frankly have a penchant for destruction (they've already broken my iPad which I had to pay to replace and my favourite bag has a disgusting stain on it from when they touched it with ice-cream soaked hands).
This isn't a one-off incident. We (mostly DP) are basically on demand childcare for his sister and that demand comes along once every fortnight.
I was WFH one day and one came around (we got the notice only 2h in advance) because the other had a football match. He was just running around the house (DP also had to WFH so couldn't be watching him throughout even though he was in the same room as DP as it's where the Xbox was). Nephew kept opening the door to my office while I was working. I locked the door. He kept hammering the door while running around despite me telling DP that I was in an important meeting and would like him to keep his nephew under control.
I love that he's close to his family. But I think there's a limit to that and I can't deal with it anymore. AIBU to think that this arrangement with his sister is unsustainable?