Ruby putting it bluntly after two years you either have to forgive and forget or move on by yourself. Only you know if your marriage is worth fighting for.
Your children probably do know (children are very perceptive) They will sense a difference in your attitude to DH at least. BUT what good does it do telling them about it now as you are still hoping to sort it?
You say you are still very much in love? So that kind of says you don't actually want to split up? Therefore, you need to work on YOU. Understand why you can't move on. Are you afraid its not over, or that he will do it again? Telling your children will not help you move on. It will only cause more friction in your family.
Of course if you do decide you can't get over this and you do decide you want to end your marriage then yes, you should tell your children at that point.
JMO
Light hearted - Confessions of a Teenager?
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