<human>: Setting: I have been hooking up with this girl for about 2 months, we are studying abroad together. She is smart, attractive, and nice when she wants to be.

I maintain that we are not exclusive and just FWB, she's cool with that, no problem right?

Except that I'm getting emotionally attached, too much for my comfort, especially because I have dependency issues and I'm certain she isn't right for me.

And, I decided to make the stupid decision to figure out what's going on with her and her ex (I read her phone messages, lots of sexting and "we are made to be together stuff" it crushes me, even though I don't want it to).

She maintains that they aren't planning on getting back together.

Question: Is there a better way to do this? Any advice whatsoever? I don't like the feeling of being second to another guy, despite the fact that I don't want to be in a relationship with the person. I definitely have jealousy issues to work on. Also, I don't feel comfortable being the "other guy" if she's leading her ex on and using me as a backup.

Really, I'm just venting, I have no idea how to do this, and it isn't tearing me apart, but it bothers me to no end.

Summarize the given text in a few sentences.
<bot>: Hooking up with girl who still maintains intimate contact with ex, don't want to be with her, but still feel uncomfortable, need advice.