<human>: Back Story: We both grew up together she went to my church. Was my first "Girlfriend" I say this in quotes because we literally did nothing. I think I was like 14 or 15. However after a few weeks of this I found out from her twin that she was making out with another guy at a football game. So I ended it. Her and I have been friends and talked on and off since than and I have always been crushing on her cause she gorgeous.

Now: Neither of us are still religious at all. But I still go to church when I am back from school to see her and other friends. Anyways during church we went to grab some food and talking. She told me she was interested in a TA who was 25. We were just sitting and talking and she knew I was a virgin but it came about again and said something along the lines of we should do something about that and well we did; from a as stated by both of us strictly FWB because frankly I do not know if I can trust her and she stated she was interested in someone else though they had not done anything.

Tonight we went out to dinner had sex again and she told me that someone from the school had told on her and the TA and said that they had had sex (which she assured me they did not (?)) and that they were no longer doing anything. 

My issue is that I think that Im starting to develop feelings for her but im not sure if i should say anything or if i should trust her. 
She is a very fickle person. Should I say or do anything? Just let it ride out as is? Is it just me or does the whole TA story sound fishy as fuck I mean there has been no school between sunday and today...

Summarize the given text in a few sentences.
<bot>: Hooked up with a chrush/ex/friend who cheated when we were much younger have always had some feelings not sure if I should do anything/if I should trust her.