My (37F) partner (37M) is not cheating, but is possibly keeping a flame alive with his ex (35F). Either stringing her along/keeping a plan B/having his ego stroked.

His behaviour (basically just keeping a strong connection with her) is not wrong or bad. I don't feel jealous, nor do I think I have the right to be, but this all doesn't feel right to me either. We have only been seeing each other for a very short while (few months), so again, I don't feel it's my place to challenge it. But is there any way I can raise it and say that I am uncomfortable about it? Or am I being insecure and unreasonable?

1. he doesn't tell me about her, I've gleaned their continued and deep connection from social media stalking (I'm not on social media (other then Reddit), from the regularity of messages they send each other and from his ongoing interest in her field of work (regularly taking relevant photos etc. to show her).

She lives over seas and he has gone to visit her numerous times in the last year alone (but hasn't told me)

We are still just dating, but I wonder if he is keeping her on (or me on) to weigh his options. I have sadly seen a number of people do this, I guess we all do at the very begining right? But I feel like we should be past this stage.

I find it really off putting and it makes me want to withdraw from him, mostly because I don't know how to raise it without casting myself as the jealous girl, rather then someone interested in standards that prevent duplicity.