I am so incredibly sorry, I cannot imagine what you are experiencing in this moment. I do not understand how one can live with the knowledge that they are breaking another person's soul. Cheating is one of the most disgusting things a person could do to someone. You will get through this, and it is vital to look forward in this moment.

*Your wife is cheating, as others have said and as you already know in your heart. Her behavior after being confronted confirms it, and a married couple in a healthy relationship do not joke about something like that, especially a man married with children. The trust is gone in this relationship, along with the relationship itself. Right now, it's important to act with purpose and conviction. *Others have recommended a lawyer, this is a good idea. At this point, you know in your heart that this marriage is over, and a divorce will be imminent at some point anyways. Seeking legal advice from the beginning will help ensure that you don't make a mistake that could jeopardize your position, and it's very possible you'll be in a stronger position anyways if you're the one to file for divorce. *Utilize your support system, I believe you have a friend that you already showed some of this information to. You will need their support. It would also be wise to come up with a course of action for yourself, and go over it with your friend. She knows you better than we do, and she could probably offer you the best support and feedback on your ideas on how to proceed. *I do not recommend playing games with the person she was cheating on you with, it will most likely get you no-where. You should go to his wife and inform her of the information you found in as much of an objective way as possible- "This is the information I found, I felt like you should see it for yourself as I would want to know as well if I was in your position, this is the conclusion I've personally reached based on this information." Doing this ensures that you remain in the stronger position, and his wife needs to know, she deserves to.

Again, I am so sorry that you have to experience this right now. You will heal, you will get through this. One step at a time from here, and you have my support. If you need extra support, message me at any time.