((HUGS)) Liz. I know how devastated you are about this, and how hopeful you were that they were building a positive relationship.
I agree that this is the kind of behavior that would enrage a judge, and would be enough for you to obtain primary placement. I'm not sure what the laws are in your state about modifying alimony, but if the situation puts you in a position of having to quit your job, you might be able to petition for an increase in alimony. Just something to think about.