I just wanted to let you know that I went through almost this exact same thing with my husband recently. We just moved to a new area, near my family, he was unemployed and having a hard time and didn’t feel like he could talk to me. He started talking to a girl he had known when he was younger. The difference is that he hid it from me and even went to go visit her without telling me. I only found out after the fact when I woke up in the wee hours and realized that he wasn’t around, as in not in the house. I opened the computer in hopes of a clue to where he was and there was a chat still open with this girl and it ended with him saying he would call her.
At this point, I tried calling him and he didn’t pick up. When he came back, I asked where he was and he lied, telling me he had just gone for a walk, in the poring rain. Needless to say, at that point, the SH** hit the fan. I freaked out at him. There was a lot of crying and him swearing that nothing happened, etc. I started snooping. I am not proud of it, but he was lying to me and I had to know what was going on. That is how I found out about the visit (and that he was planning another one). I told him what I had found and told him that he would not be visiting her. While I don’t condone snooping (you really do always find stuff, by the way) I was honest with him about what I was doing and told him that the only way I would feel comfortable that nothing was going on was if I could see it.
He felt really horrible about it all, but still doesn’t understand that what he did was a kind of cheating. He says that he never really thought that it was a problem, since nothing (physical) was going on. He really didn’t understand the boundaries that exist when you are married / in a committed relationship. I have to think he at least had at least a subconscious thought because he lied about it, but he claims he just thought I would have a problem with him being friends with a girl.
We have never had any kind of issue like this in our 10 years together. I totally trusted him. I NEVER would have thought that something like this could happen. He is having a hard time realizing that this has changed our relationship and I am having a hard time trusting him again. We are working through it, but it is hard.
I guess the point is, talking to her about it is key. If you feel uncomfortable about it, it IS a problem, even if nothing (physical) is going on. Having an emotional connection with someone of the opposite sex can be just a painful as having a physical one. She may not realize that what she is doing is inappropriate (from your talk with her, I assume this is the case) and just feel like she can’t really talk to you. That doesn’t make what she’s done okay, and I think it is important that you make that clear, to keep something like this from happening again.
I know that things will work out with me and my SO, and I am glad that your problem didn’t reach the point that mine did, but don’t feel like you are over-reacting. As many have said before, this kind of thing can be a slippery slope and a good relationship is worth fighting for.