Even though it has been some time since I went through what you are going through, it still disgusts me to read about such things.
For me, it was a boundary she broke as she had agreed to not introduce the kids to other men. She broke her promise and blatantly exposed the kids to her affair by kissing in front of them and even having OM kiss my daughter. My daughter was led to believe that it was cool that mommy had both a husband and a boyfriend. When I first learned from the kids, I was both heart broken and in a rage at the same time. This, along with her threats of finding a rich guy to buy the best lawyer in town caused me to strike fast and hard by filing for a divorce and a protective restraining order to keep the kids living in my home.
I resorted to the Final Last Resort that Michelle mentions in her book. Over the year following my filing, I detached and gained emotional strength. My wife noticed the change of me not being a doormat and right before the D was final asked for another chance. But I had no desire for her anymore as she was selfish and had not taken any steps to prove she really desired the marriage to me.
My main advice, as many others will say...learn to detach from thinking too much about your W and OM. Improve yourself for yourself and your kids. It is not easy, but if you keep your focus on the kids sake, the rest of your life should fall in place. There is no guarantee that your wife will have an awakening, but I believe that because you have kids together, it will cause her more often to reflect on what is important - family.
And a backup effect of your detaching and GAL will be that if she does indeed push for a divorce, you will be that much further along emotionally so as to carry on with you and your kids lives post D.
