I guess discuss with your kids and see what D8 really wants? Kids come first. But I also think if you don't stick to the schedule already set up, I mean at least roughly, I do switch Frid. and Sat. nights with H when he or I have stuff, but he just gets the 2 nights a week, and prob. stick to that.
I think consistency is good for kids, and it seems like this could be a long-term ongoing problem if you are too loose with the schedule. I have to say I don't have that problem, so I know that's tough. (((((kat)))))) Oh, yeah, and I also don't like the kind of sneaky, underhanded way your H handled that!!!