I totally understand why you are pissed off. She scheduled a vacation knowing full well it conflicted with the parenting plan and did not try to negotiate with you first. If you give in, it could set a precedence that she can just do as she wishes in the future.
Quote:
she will let the kids know I put a kabosh on it
This is huge BS. It is called parental alienation. Call her out on this. The kids should have no idea of parenting scheduling conflicts.
Tostada, I feel for you man. It is not going to be easy dealing with her. But it has been done before as in this case. Study up and learn from the past but look to the future.