I'm kind of surprised she hasn't had you served with the papers... does she have a lawyer or is she trying to do this herself? I imagine the more you ignore her, or put this off, the angrier she's going to be... and the more she's going to blame you. This is a convenient excuse for anger, making everything your fault (i.e. she feels you ignore her, never listen to her, etc...), and helps her feel better about her behavior and any guilt (if you are so unreasonable, she believes she has a perfect right to do this).
Just continue to try and be calm in dealing with her. You will feel better about yourself and have no regrets... you won't be playing up to the anger or acting like the sort of guy she would want to leave. Unfortunately, if someone wants a divorce bad enough they can get one. It takes two people to make a marriage, and only one to make a divorce.
One more thing, if I were in your shoes I would calmly let my spouse know I'm aware of the OP. Affairs thrive in secrecy and sometimes once the secret is out the relationship deflates. Don't throw out blame or anger. Just be matter of fact.
There is no arriving, ever. It is all a continual becoming.
