Where does the fault lie i.e. who is the more wrong person?

I'll start by saying I snooped. I snooped her blackberry. I understand that this was wrong. I regret it considerably.

I discover, however, that shes been having conversations with her ex. This in and of itself doesn't bother me, they havent dated in 20 years, and have maintained a close friendship over that time, even through his marriage.

She travels to her hometown for a visit about a month ago. He is recently divorced. They hung out and caught up and thats all well and fine, she says nothing happens and I believe nothing happened between them. In fact, I know nothing happened. Thats a non issue.

Let me explain the snooping. Ive never had trust issues for one, but one morning before work I couldnt find my phone, so I used hers to text mine so i could locate it. Upon opening her text inbox though I discover a large volume of texts between them. Curiosity gets the better of me and I peruse a few. I over react to the context of a few texts and get upset with her. She gets upset with me, but eventually we manage to get past it.

Fast forward a month, and I am drunk and shes outside smoking and I'm waiting for her to finish. Her phone is there and it beeps. Its the ex. Curiousness + drunkenness = I wanna read 'em.

This time there is no confusing it. Texts about how she misses him and wants to be there 'smooching him' and how shed be baking him cookies and how she loves when he calls her her 'cutest'. Nothing concrete about any specifics, but its clear, the girl i'm dating is having intimate conversations with another man.

Now, here is where things get a little uh, well, where I make an error in judgment. I contact him. He knows who I am of course, and basically, I ask him how he feels about her and if he'd like to pursue something with her and things like that, considering their extended relationship over the years. He says yes. I respect his honesty on the issue, and I even wonder that the girl might be interested too.

(This is where I mention that there is a significant age difference between me and the girl. I'm 26 - Shes 38. And hes 40ish. I say this to point out that I know that there is no long term plans for the girl and I, but I do want to see her happy and maybe this guy is actually the answer. Sub question here - Is that a messed up idea? A guy trying to set the girl hes with up with someone else?)

Anyways. I confront girl on the situation. That I snooped her phone. That I talked to her ex. I tell her that he wants to be with her. That I think she should pursue it if she wanted to, but that if she didn't she shouldn't be leading him on.

Girl is upset with me. 'I went behind her back' and I invaded her privacy (this part is true). Girl thinks what Ive done is the greater of the two evils here.

So I'm writing all this to ask the simple question, who is more wrong in this situation? If I had never snooped nothing would have happened right? And they never fooled around while she was there, nor was she intending on any time in the immediate future.
But then again, she shouldnt have been having romantic conversations with another man right? Isn't that too going behind my back?

What do you all think?