First of all, you don't ask him to not do it in front of the kids, you tell him. And no, I'm not saying you should necessarily ask for separation or divorce because of his actions. What I think we're BOTH saying is, that there is a basic fundamental level of respect that you need to ask for from important others in your life, and I strongly suspect that you've been allowing your husband to disrespect you in a number of areas and it's part of the problem.
This is an opportunity.
One of the positive side-effects from the HORRIBLE situation of infidelity is, we get to work on ourselves, and out of it can come tremendous strides, if we are courageous. You -- like me -- I think have more of a boundary-setting (and -enforcing) issue than you have even a marital issue, and you need to learn how to better handle it.
Can you think back, as best you can, what were the actual words you used when asking your husband not to carry on right in front of you? Can you give us a pretty-close dialogue, both yours and his? Perhaps we can help you with what you might have said.
One thing that comes to mind immediately is, when he said "You can't stop me from having an affair," I would have said "No, I can't -- that's your foolish and selfish choice alone, and I won't accept any responsibility for it. But as the mother of our children, I can DAMNED sure tell you that I won't allow them to be harmed in this, and I also will not allow you disrespect ME, in FRONT of me. So I suggest you go do that someplace else. My patience is not limitless, and I will no longer tolerate the disrespect."
If he refused, and just kept e-mailing her, then the next time he came from from being with her, I would have had all of his sh_t out on the front lawn, and the locks changed.
Jesus was a loving, patient man. But he also knew when to throw over the money-changers' tables and summon up His righteous indignation. "Righteous indignation" is what you're going for, Karen -- not pettiness, or meanspiritedness or even just raw anger. Think "mama bear protecting her cubs."
