Cause for concern?

I need some impartial advise and I hope that perhaps you can tell me if I have any cause for concern or indeed if I am over reacting: Last year I came across an email conversation my wife was having with a guy she was working with. The conversation related to a works night out the previous week – which my wife attended and stayed out. The conversation made mention of how the both felt the morning after, albeit it did not say they had slept together. Being slightly upset and suspicious I asked a friend if he could do anything, to which he was able to somehow bug her computer so he could tell what she was doing. The long and the short of it was that they regularly had very flirty/intimate conversations. I also believe but cannot prove that they sent intimate pictures to one another via their mobile phones. When I confronted my wife she did admit to sleeping in the same bed as the guy but insisted that they had never had sex, she did admit to being very flirty and being stupid – she then said that I was to blame and that I neglected her and worked too hard etc etc. We got past this and I thought things were okay, until recently. I had started to notice she was keeping her mobile on silent and very close to her. She started to use her laptop again saying she was talking with friends from work, she even showed me the women she was talking too. I also know she has been speaking with a guy from work, who she says she does not really like and he is a computer nerd etc etc. Asking my friend to check he was able to tell me she is indeed having flirty conversations with this guy along with sending him intimate pictures, I also believe that they go to lunch together on occasion. There is even a conversation about what they would do to each other if they were together, there was even a conversation about him dropping in to see me to talk to about something and while I would be upstairs they would have a quick fumble – or words to that affect. Added to this we were talking about having children at the beginning of the year, but she now no longer seems interested. I am ready to call it a day but before I do anything rash I just wanted to make sure I was not overreacting. I know that spying on her is not good, but if I did not I would not know what I know now, be that a good thing or not. Any advise most welcome....

hi,my opinion on phones being on silent and always in their pockets is suspicious for me anyway my husband was in contact with an ex behind my back and his phone was off or silent and always out of sight i went thro it many times and found out eventually that my gut instinct was rite he now has a new phone and he leaves it around because he tells me she doesnt have his number ,what does your gut instinct tell you,and you say she has said this man is a geek have you seen him,is he married,the thing is it will eat at you and it wont go away,talk to her and tell her how you feel.