Thanks for your thoughts - each of them gives me a different viewpoint to look at this situation.

By the way, she is currently at her parent's place going through the family lectures and having stressful time. A private person, her family discussing all this is taking it's toll on her.

IF we are to continue, here are the terms that I have thought of:
1. Written legal acceptance of cheating and apology etc. Only to be used in future if at all needed.
2. We give these three guys something to think about all their lives. Example: let their spouse know, physical impairment(yes, I am still thinking about it and ready for consequences)
3. She loses a finger
4. We share passwords etc and don't keep secrets
5 If this repeats in future someone/more than one, gets killed right away. (I am ready for consequences and crazy like that)

Other option is divorce and going through all the pain that comes with it for everyone - specially the kid.

I have let her know that she can decide how she wants to move ahead.

She is back only after 10 days and then we discuss, fight, decide and I share here.

Problem is my thought process is swinging like a pendulum. I am convincing myself of divorce in the morning. By the night, completely convincing myself that divorce is not the solution for me and breaks everything apart.

Whatever happens, she will go to hell for doing this to me and my family.