Search Results: good and bad qualities

I met this guy online as he was returning from a five-month trip through Asia. We were very open about our partners, history from the start. He "collected" flags during his trip, and got close to one girl in particular but told me, how it was just a fling and nothing more so I didn't bother asking more. We connected so well, and even better in person that I just assumed that she was out of the picture, and that we were both focusing on us fully.

Fast forward to today, we've been dating for a month and half now, and he's still in touch with this girl from his trip. They don't message daily, but definitely stay in touch through Facebook messenger. I know in his mind, he thinks he's not cheating. But she likes to reminiscence about the "good times" they had, and how much she'd like to meet up with him, and even try to get him to Skype her (just once so far) ~ and even sent him a sexy pic. His response overall has been agreement > he said yes to Skype, and responded with the heart-eyes emoji to her sexy bikini pic. I feel like she offers him a different quality that we don't have yet in our relationship, a kind of emotional connection that takes sometime to build. I just don't get how they have it in two weeks, while we've been together for a month and it's just starting to form.

I'm not really sure how to deal with this. Part of me, wants him to just stop talking to her, but I feel bad expecting him to drop a person who really does seem like a nice person (she is!). I just wish he would make his relationship status clear with her, at least that way, I'd know whether she could just be friends with him, or if her intentions really are different. I don't want to inhibit my boyfriend unfairly, but I want to be able to build a strong foundation for a relationship with him. However, knowing that this girl is in the background makes it really difficult for me to be relaxed, and not be "fake happy". Please help! I want to fix this, not break it! I really do like him :(