I struggle with this also. H doesn't even follow standard visitation yet, (which in Texas is one day a week, usually Wed. or Thurs., from the time school gets out until 7 or 8pm, and every other weekend from 6pm Friday til 6pm Sunday) even though he agreed to it in our Temporary Orders Hearing.
I do feel taken advantage of, and often feel that I am enabling him to continue. But then I think about the kids and what's really best for them at that moment. And I think that's what you have to do, too.
When your W is acting that stressed, how is it affecting the kids? Is it affecting her parenting skills? Would she "take things out" on them? What would be better for them?
Your W may be using them to manipulate you, so you do have to be careful of that, and she is going to have to learn to cope better, though, so I think Nature Girl's suggestion of not immediately offering to change your plans, but offering an alternate time or day is great.
It's a lot like navigating through a minefield, isn't it?
If anyone here has a minute to check out my thread, I would appreciate it!
Me:40, xH:41 M:19 T:21 D14, S10, D6 IDLYA bomb:12/22/06 OW bomb (21 yr. old employee):12/23/06 H move out 2/07, OW move in 5/07 D papers served 6/07 D final Nov. 26, 08 :-(