Recently separated and in need of some advice

The reason for the seaparation briefly is that I suspected my wife of having an affair about 4 months ago. I confronted her and this led to her saying that she would not be accused of this and that it was the end of our 17 years together (7 of which married). I couldn't accept this and looked for evidence of an affair. I found stuff on her phone and Facebook but nothing absoluletly incriminating. I again confronted her and she admitted to seeing somebody at her work and that they had slept together. She later retracted this admission but still insisted that she wanted a divorce. We have been in separate rooms in the same house for the last 4 months. I have recently found out from other people that she has slept with this guy but she says because it was after we separated it is not considered as adultery, is this true?
She has also now slept with another guy of which I do have written proof (email), would this be considered as adultery.
As yet neither of us have filed a petition for divorce, she expects the the divorce to be on the grounds of separation over time. Any help with this mess would help. I appreciate the fact that she has commited adultery wil make no real world difference but it would make a difference to me. Thanks

Hi, you have proof of adultery so no probs there but only if she admits it or u have the guys full name and pref address. doesnt make one bit of difference to the court, what u file ur petition under, the results are the same. it is still classed as adultery as u r still married. if it would make life easier and less aggro tell her u would be willing to compromise and go for unreasonable behaviour, it might save u a lot of money, time and recrimminations later on, even tho u get the satisfaction initially
kind regards
dawn