Girlfriend hiding she met with her ex?

I don't know if I'm wrong in feeling jealous here, but. Things haven't exactly been rainbows and sunshine between my girlfriend and I lately, AND recently she seems to be getting a little bit more emotional (in a positive way) when talking to her ex boyfriend and first love. Of course, I am fully aware she still has feelings for him. She herself informed me that she still loved him during early days of our own relationship, but because of his constant betrayals and cheating on her in the past, she told me that they could not be together (he is now married to another woman now and taking care of children that are likely not his own). She has told me, she still loves him, but is in love with me.

Now, recently, I myself have betrayed her trust but not by way of cheating or anything that comes close to the magnitude of what that other guy has done. I disclosed confidential (financial) information that was solely her business to my family and she trusted me to keep it in confidence... So now our relationship is trying to work it's way through mending trust.

Just a few days ago, she leaves in the morning without saying a word (while I'm still asleep). Posts on fb simply that she can't stop smiling. I ask what happened upon reading this and she says that she "had breakfast with a friend". Funny, it's been a LONG time since she's been in such a happy mood that she can't stop smiling. She certainly doesn't smile around me much anymore. She returns that afternoon (made apparent through text), then I see her for two seconds that night and that's where she first told me that she actually left town. Leaves, stays at a friends house, I finally see her the night of the next day. Still doesn't say much about what she's been up to.

Now, I know I'm really jumping to conclusions if I'm assuming that she met her ex at her hometown. But I just can't shake the feeling. The timing and situations just seem to stick out too much too me. I'm I being paranoid? And, say if it's true. Is it right for her to keep the fact that she met with her ex, specifically, hidden?

I don't blame you for freaking out a bit. I would, too.

But yes, you are jumping to conclusions. You are being paranoid. You don't know the whole story. It's reasonable to be guarded right now. Anything can happen. When I was in a similar situation, my then-girlfriend went to lunch with an ex, they had a good time together catching up, and that was that. I was feeling a bit insecure, but I was also happy for her.

Let it go for a bit, but feel free to bring it up later. Try to just be interested in her and her happiness. But be realistic, be guarded if you must. It's a tough line to walk.