The description you gave about your Wife all the way down to her Name is just disturbing to me. It sounds like we're married to the same person.
If she is truly having a life crisis and an affair, then maybe you should look into the MLC Forum and see if you can pull some information from resource threads.
As far as the Affair goes, there is nothing you can do to stop it if she's not willing too. Sandi is dead on with the word "consequences" and more than likely when you confront her with ending the affair or move out, she WILL choose OM. I think she needs to really know that you will not tolerate an open marriage and follow through on that particular consequence.
As far as just filing Divorce to shake her up. Let me ask you, do want a Divorce? I mean DO YOU really want a Divorce? If you follow through and it doesn't work in shaking her out of the fog are you going to be looking in the mirror with regret that you didn't try something differently?
You have every right to be angry and feel betrayed, but forgiveness is the gift you give yourself.
