Divorce Support Forums: Wife's Infidelity? Yea or Nay?

My wife and I have been married for 17 years this May (we are both 40). When we met, we dated on and off for 3 years. I proposed to her and she put me off for 6 weeks before I basically demanded a yes or no from her. She said yes. However, she was waiting the entire time to see if another boyfriend, whom she dated for only 4 months prior to meeting me, would throw his bid in and ask her to marry him. That's how we started and this guy has been the bogeyman to me ever since. Thought after 16+ years it was old news. However...

Last February (2007) I bought my wife a laptop for her birthday. Soon after in March, this same boyfriend reconnects with her by email. They begin trading pictures of each other, their kids, etc. My wife became increasingly distant and self-absorbed, spending a lot of time on the internet. In May, I was preparing to go away for a year to a school about 120 miles down the road, leaving the job I loved forever in order to put our family in a different income bracket.

At the beginning of May, my wife declared that her old boyfriend was in poor health and that she absolutely needed to see him. She wanted to buy a plane ticket on short notice to fly down and spend 4 days with him regardless of the fact that his wife would probably not be too happy about it. I said no on the basis that we didn't have the money and I would be starting school soon. To make matters worse, my wife wanted to go down to see him the weekend of my 40th birthday, which was also the last weekend I would be home before school. While in school (a medical program), I was unable, as anticipated, to come home very often and wanted us to spend a special family weekend together before I embarked on this academic mountain climb.

One weekend prior to my birthday, we hardly spoke at all. I took care of the kids myself and she spent the entire weekend on the laptop or having private cell phone conversations in the bedroom. On Tuesday, while she was showering and I was feeding our daughter, her cell phone rang with a text message. I answered it, thinking it was a message from one of the other teachers at her school regarding an illness or something and I intended to relay it to her in case she needed to quickly arrange for a substitute. Message was from her old boyfriend, asked how she slept, said he missed her and sent his love.

What I did next was not very nice but, as soon as she left for work (I had the day off) I hacked her email, read copious love letters from him that she tried to hide in an "internet offers" folder, and her replies which she did not realize were saved as copies in the "sent" folder. A reference in one letter lead me to her brand new iTunes account (started that weekend) with a single downloaded song by Bon Jovi which describes two old lovers with families of their own getting together again for old times sake in a hotel room. I tried to check her phone records on our cellphone family plan only to find out that I was now a user but not a customer on that plan and could not have access to those records.

When she came home, I calmly confronted her. She was emphatic about letting me know that I was overreacting and that all these maneuvers were in no way related to marital infidelity. I said giving your heart to someone other than your spouse, even my phone or mail, was infidelity. We talked it over and during the summer months came to an agreement that it was all over between them and that we wanted to stay a family. However, since I foolishly dug up info and let her know about it, if she is continuing any correspondence with him, I probably will never know now.

So, apart from my breach of her privacy, my question is this: was that cheating? Am I just making a big deal out of nothing? Over the years I have had numerous opportunities to have affairs with other women who were very interested in me and simply refused. I would never have guessed my wife would do this; I always thought I would have a lapse in judgment at some point and not her. Had she flown to see him and had I not discovered all the correspondence before going to school for a year, who knows where my marriage might have ended up? She says it was a limited thing and no big deal. I say I nipped it in the bud (maybe) and didn't give it a chance to go anywhere.

What should I do now? I am suspicious of her now and wonder if she has any true feelings for me or am I just a convenience. What is your take?