<human>: So to be brief, back in March my girlfriend admitted she liked a new friend of hers.  We live together, and she was very obviously sneaking out at night and staying out all night.  One time I caught her getting in his car.  She denied anything but friendship, but one night she was texting like crazy, and I saw a few of them, she was calling the guy out about "using her".  I confronted her, she broke down and cried and admitted to cheating.  It was a rough emotional time, and we nearly broke it off and moved out, but we got through it, and everything was good... so I thought.

Anyway, last night she left her gmail open on my computer, and I couldn't help but check, and sure enough she's sending him e-mails saying "Glad I got to see you again last night, you're so handsome, I can come over again next week."  Granted this isn't proof of fornication, but it's proof of an emotional affair where there once was fornication, and if she's sneaking off to his place and calling him handsome and meanwhile telling me she hates his guts and doesn't respond to his texts, I know what's going on.

I still have her e-mail open, and I'm trying to think of anything I can do to route the two of them into a confrontation.  I know what has to be done, I have to tell her I saw the e-mails, that she broke my trust and that we can't be together anymore and that she has to move out.  This guy has been especially evasive with me and I have always offered to peacefully talk about it, but when I've confronted him in person he lies to my face and then texts her insulting garbage about me, so yes I have somewhat of a vendetta and would at least like to get some vindication.

Summarize the given text in a few sentences.
<bot>: Girlfriend left g-mail open on my computer, found confirmation of cheating, looking for good way to use this e-mail access situation to my advantage for non-violent confrontation and vindication.