Long story short my husband has agreed that his kids can come to us later this week (not one of the usual days) which is absolutely fine. Their Mum had something on.
He was originally going to take the day off work, he is self employed so it's easier for him to take days off short notice.
I am off that day but I am meeting my Dad out for the day with our DD (mine and DHs). It was arranged long before this situation ever came up. I don't see my Dad much as he lives a bit away.
DH has now said he's really busy with work actually and can they not just come with me for the day. I feel like he agreed to his ex to look good and then almost immediately decided he was too busy actually and was hoping I'd just do it after agreeing.
AIBU to say no sorry I have plans. My Dad doesn't get to spend much time with his grandchild and I wanted this day to be between DD, her grandad and me just focused on her. We've really been looking forward to it. My DSC argue a lot between themselves sometimes (close in age) and I just don't want the dynamic of a day we've been looking forward to, changing with more kids to look after.
He agreed to it and should have thought if he was too busy with work beforehand.