I can relate to what you’re saying, as I have jealous tendencies as well. When Fiance and I started going out, I was really insecure about one of his exes. It was irrational, because I knew that she wasn’t particularly good looking, and she did some pretty crazy things when my Fiance was dating her. I felt particularly jealous of a couple of trips they took, and I felt insecure because she apparently got on so well with his friends.
The friend issue was caused by the fact that my Fiance and his friends go back years and years, and in the beginning I felt like I didn’t quite fit in because I am about 8 years younger than Fiance, and didn’t share their history. Gradually, though, I felt more and more part of the group, and now I don’t really feel like an outsider at all. I also learned through conversations with Fiance that none of his friends considered this particular ex ‘marriage material’, as she was basically an irresponsible, drunken skank. She ended up having a long-term affair with one of FI’s friends before ending things with Fiance.
As for the two trips he took with this person, I don’t really care anymore. We have taken several trips together abroad now, and we’re planning an amazing honeymoon. Whenever he mentions those places he visited, he never mentions the ex, because she is simply not relevant to the story.
My insecurity started to fade gradually when we moved in together, partially because he had never lived with any girlfriends before, so it really felt like it was new and special to both of us.
I know it’s been hard for Fiance to deal with my insecurity, but he has been very understanding as I’ve been very honest in why I feel insecure (I know that it’s connected to deep self-esteem issues). He’s also been very helpful in that he got rid of all his ex-girlfriend stuff after we moved in together, because I told him how uncomfortable it makes me to have them in OUR home (and just to be clear; I don’t keep ex-boyfriend stuff either because I don’t feel it would be appropriate for a soon-to-be-married woman).
I no longer feel uncomfortable if an ex is mentioned (although that doesn’t happen very often), and we’ve been able to have some very lengthy discussions about our past relationships and why they failed. And he’s never said anything like “This person made me like this and this book” etc., which really helps.
So what I’m saying is; the insecurity will fade away eventually, because as your relationship grows the exes will become more and more distant in time and in his memory.