Well, I think it's important to directly confront a cheating spouse, so that you show a strong, principled stand, and so they know you're fighting for them, for your marriage, and for your family.
And I think Allen's advice about asking a family therapist, and your immediate and/or in-law family, to help persuade a wayward spouse is also important, because it exerts important, third-party influence (you are, after all, a totally biased party/vested interest here).
Make sense??
Puppy
"What is best for my kids is best for me"
Persevere = happily being patient over a long period of time