I see taking your girls on vacation w/o wife's knowledge as trying to get even. I'm not sure it's a wise decision. She could turn around and try to do the same thing to you. I think it would be best to inform her. I do understand that they are children, but you do not want to get in a power struggle with her. I think you could approach it as you said, it's a way for you to get away and time for her to have time to herself. I know that we all have been hurt so bad, but if we want to stand for our marriages, we can't burn our bridges.
Life's challenges are not supposed to paralyze you, they're supposed to help you discover who you are. -- Bernice Johnson Reagon