There is no way in hell something as important as telling your children that their parents may DIVORCE should have been done by your wife, unilaterally, in a fit of anger. That is unconscionable.
My own personal opinion is that you should sit your kids down separately and tell them in an age-appropriate way that their mother has a boyfriend, and that married people shouldn't have boyfriends and that you are not okay with that, you've insisted that she stop, and that she refuses, and THAT is why the marriage is in crisis. That this is NOT their fault, that you do NOT want to divorce their mother, that despite her bad choice you still love her very much, and that they should to, but that their mom is just very confused right now. You should also tell them that she is angry with you because you told the truth, and that she'll probably even be angrier when she finds out that you told the truth to THEM, but that you will ALWAYS tell them the truth. ALWAYS.
And for god's sakes, tell them it's NOT their fault.
It's time to rein-in the Entitlement Princess, for you to take control of the agenda, the timeline, and the consequences. Your kids need a hero right now, and it AIN'T gonna be their mother.
