<human>: Can you provide a brief rundown of the text in within 3 sentences?

(33m) (27f) We have known each other for three years, dating for six months. I was in a  relationship when we met, she was single and actively dating. I ended my  relationship to be with her.

 Shortly after we started dating I noticed her son kept calling me by another guys name which made me suspicious. So I snooped in her phone and it was confirmed that there was some sort of relationship going on with this other guy who lives out of state. Texting that was sexual in nature, exchanging pics, ect. 99 percent of it was before we were official. So I bit the bullet and confronted her about it and my snooping, and my feelings about how it makes me uncomfortable. She admitted it was inappropriate to talking like that to this other person while in a relationship and said she would fix it.
 
Five months later and she is still talking to this guy behind my back I have come to find out. Also, her best girl friend who is in jail, and who she corresponds with regularly mentioned casually in a letter that she is not aware I read, if my gf was really that happy with me and has she thought about cheating? Like it's no big deal.. 

I will be confronting her again today  due to the fact she is lying to my face about this and other things, like introducing me to her guy friends or talking about them without mentioning that there was a previous thing with them when I know that to be untrue. Also, is it strange that she secretly keeps track of our sexual encounters in a  calender type organizer( days we have sex get highlighted) Any advice would be welcome. Our sex life is good and we get along great otherwise.
<bot>: gf talks to other guy behind my back after I expressed it bothers me and is now lying by omission about it and other things as well.