<human>: Can you provide a brief overview of the text?

Pretty much my girlfriend of two years has been talking to another guy behind my back. Everything seemed fine at the time, but I did however notice how tired she would always get during the day. When I confronted her about this she just gave some petty excuse such as she just couldn't sleep. But keep in mind that this has been going on for about a month. I got too suspicious and actually went through her messages, to find that she had been waiting for me to fall sleep to talk to this other guy from midnight all the way until the morning ~6am. When I asked her about this she tells me that he's just a friend and that she just needed someone to talk to. I still do love her very much ,but im not sure about what i should do from here.
<bot>: gf of two years has been talking to someone behind my back for a month from midnight until morning, when confronted says he's just a friend