Forget exposure for now; it sounds like that's a dealbreaker for you anyway, and it's distracting us from the broader points. You need to do SOMETHING differently than what you've been doing, SOMETHING to throw her off center and "shake the tree."
I would suggest considering one or both of the following:
1) Seeing an attorney, for a broad consultation to merely discuss options and potential threats to you -- preferably one who specializes in "men's rights" and paternal custody matters (which you should be doing anyway), and let her know that you did (but without going into any detail; just saying "to better understand what we're facing, and what some of our options are. I felt I needed to protect myself");
2) Discontinue MCing, as it's rarely effective when one of the spouses is in an active affair anyway. Let her know that you'd love to go back and address ALL of the issues in the marriage -- including yours -- when she ends her affair and comes back to work on the marriage. Consider continuing to see a good IC, just for yourself;
The way I see it, she's not "in" the marriage right now, and you have agreed to unilaterally disarm and rely on, and trust, someone who does NOT have the best interests of your family at heart right now, that being your wife. Until she agrees to come back and actively be "in" the marriage again with you, you need to protect yourself. That protection is financial, it is legal, and it is emotional and it is spiritual. I'd suggest you come up with a plan to button down all four of those areas, and then just focus on YOU, as your wife decides what it is she's going to do.
