<human>: I dated Tom for about 5 months until he broke up with me. This was back in '13 and I've since started a new relationship. 

A month ago, Anna started working where I've been working for the past two years. We're going on a work related trip in a month. Two weeks ago she found out I used to bang her boyfriend. A "friend" let it slip. I've noticed Anna more distant and aprehensive ever since. 

I can't help but feel a bit jealous and VERY curious. I hadn't thought about Tom in a VEEEERY long time and suddenly he's all I think about. I wonder what "could have been" and also fantasize about him picking up Anna when we come back from the trip and seeing me and I wonder if he now thinks about me. 

The trip we're going on is very relaxed by nature and we're not allowed to leave the premises where the events are to take place. I've gone on the same trip before and I shared a room with my coworkers last time and we talked a loooot about our personal lives since that's all there is to do. Another coworker, Jennifer, is coming along as well. I don't think she knows that Anna and I have this history.

What can I do? I don't want to play dumb and ask her about her life since she knows I know who she is. I worry Jennifer might pretend everything is cool and unknowingly make things awkward. I've only known  Jennifer for a few weeks too. 

thank you so much for reading!!

Can you condense the text into a few key points?
<bot>: ex's new girlfriend and I are going on a work trip. How do I handle the situation and how do I stop thinking about my ex?