Usually, these wild accusations come out of THEIR guilt.
I wouldn't be surprised if she's still carrying on with the married man. They start to project what THEY would do if they were in your shoes, if you knew the whole truth about their behavior.
Stick to the high road, stay detached. Show your kids that you are the strong dad they can rely on. Let go of your wife, look towards building a fabulous new life for yourself.
Note - this doesn't mean all hope for your marriage is dead - just that the best hope for it is for you to let go and work on yourself AS IF things are over.
