My DC (5) see's their dad (my exP) regularly. Their bedtime at home is 7:30. When DC stays with their dad, they go to bed anywhere between 9 and 10:30. DC has had a few quite serious health problems over the past year, and although they are almost back to normal, they are quite tired most of the time, and really need to be in bed at a reasonable time.
DC comes back home after a night at their Dad's, and they are shattered and grumpy, and it effectively rules out the rest of that day for doing anything as all they want to do is lie on the sofa (or moan awkwardly non stop!).
I have spoken to my ex about the late nights, but his response is a late night now and again won't kill them (it's once a week, including school nights some times, and DC is 5). And then he continues to put them to bed late.
Does anyone have any ideas on how I can try and deal with this? I never get involved with what my ex does with DC on their time, but this is really effecting my child, they are tired, tearful and miserable due to not enough sleep every time they come home!