Telling the truth is important. I will not say anything to my kids, esp. something so important, lies that I don't consider truthful. Having sais that, what is true to you and what is true to the other party is different. You can tell your kids that you are not breaking the marriage vow. You still believe in it. That is true. However, your wife believes that it is OK to break the marriage vow under her "special circumstances". She is an adult and she makes her own choices. While you may not agree, you respect her choices. If she is very religious, from her standpoint, it is also a very difficult choice because she knows she is breaking the vow. She must be very unhappy that she is willing to do this. (or whatever twisted reasons that WAS always come up with). As human, we may not be as willingly forgive as God, but we are always trying to be more understanding, more embracing, more forgiving. I would try to phrase my wordings to the kids based on loving wordings, rather than right/wrong wordings.
I always tell my kids, "You are a kid now so I am making choices for you. However, you have to learn to make your own choices because ultimately you are responsible for what you do, not me. You are going to school and learning everyday what is right and what is wrong so you can make good choices. If you make a mistake, you learn from it so you won't make the same mistake again."
LO, I think your D4 is very secure. My kids are too. She will be OK as you will always be there. I once complained to the teacher that my kids never hangs on to me, just "bye mom" and they are off (to grandparents, friends) and never ask for me for hours. The teacher said, "that's because they know you are always there. they are secure". Good job.
