I see the fine point of your clarification, but really it's another way of casting doubt on his ability to, what exactly? Keep them ok? Keep them from getting cranky? Keep them alive? If I were in your shoes I'd be thinking that telling him he can only have two days might protect him from overextending himself and getting frustrated or not having a good time with them because that third day away from you was just too much. Let him be. You figured out parenthood, he will too. He may not handle it the same or as well as you think you do, but it is more important for dad to feel confident taking his kids for three days on his own than it is for your kids to not be cranky one day. He'll do fine.
Or, he'll decide he'd rather not take them out of school for that extra day, but let that be his decision, not yours.
It was sounding for a minute like your cool city experience with them was more important than school, but H's would not be. Really?
You are doing amazingly well for so new in your sitch. Keep growing.
Adinva 51, S20, S18 M24 total 6/15/11-12/1/12 From IDLY to H moving out 9/15/15-3/7/17 From negotiating SA to final D at age 50 5/8/17-now: New relationship with an old friend __ Happiness is a warm puppy.