It seems to me that she just lost her kids. She demonstrated that she does not have the best interest for the welfare of the kids in mind. Jumping back and forth between you and the other guy could be construed as disserting, and also inflicting emotional distress on the kids because of this other guy (if they know about him).
Consult an attorney right away, and get a grip on what exactly it is you need to do and NOT DO to come out with your interests met. Find a lawyer that works with the father's rights in mind.
I am aware of someone who recently got divorced, he got the kids, the house and is not paying her anything (not sure if she's paying him or not). So contrary to popular belief, it's not always the woman that winds up on top.
I would not suggest hiding your money or anything like that. Play it by the book, because if you don't and get caught, you'll have a lot of explaining to do. Be the best dad you can be, and be prepared to provide proof. If you have mutual assets, put them into an accout only you can get to.
Begin gathering information on your wife. It's better to be prepared for the worse, and it sounds to me like that's what's brewing. Keep track of her comings and goings, what she's spending on whom, phone calls...anything you think might help you.
From what you have said, I see no reason why you will not be able to wind up with everything. After all, she made the biggest marital mistake anyone can, and is going back for seconds.
Go to the bookstore or library, or jump on the Internet...there is plenty to read..............