<human>: We've been together for three months, and after accidentally seeing a text message on her phone from an ex of hers, I perused her facebook messages while she was in the shower. What I discovered was a series of conversations reminiscing about past sexual exploits, obvious flirtation, and hints at future encounters. 

While I feel guilty for letting my suspicions drive me to violate her trust and read her private communications, I feel very upset that she has been commiserating with her past lovers so explicitly during our relationship. Last week she told me she loved me (I told her I could not reciprocate), and now I uncover her unfathomably dirty laundry. 

Forgive me if this is a simple question or one often asked, but what am I to do? Should I confront her about it, and be open about my snooping (she has in the past offered to let me read her text messages, which I didn't accept)? I value our relationship, but the thought of her colluding sexually with others makes me ill and erodes my respect for her (as my snooping erodes my respect for myself).

Can you summarize the given text in a few sentences?
<bot>: Read girlfriend's facebook messages, discovered sexually-oriented flirtation with former flames, want to balance respect for her privacy with concerns for my health & our relationship.