<human>: So I guess I'm looking for reassurance more than anything, I love my boyfriend, and would trust him with my life.
For the sake of this post, I'm going to call my boyfriend Zach.

Zach and I live in different towns for work, but we see each other regularly, and during the holidays. Last summer he admitted that he was confused about his relationship with one of his closest female friends (lets call her Jenny). Jenny is a nice person, and we get along, but as we live about three hours apart, I don't hang out with her as often as Zach does. As he spent a lot of time with her last year, they got close, and after going on a few trips together (alongside about 20 other people, who did notice, and comment on how close they were) he confessed to me that he thought he might have feelings for her. I was devastated, but we talked about it and he ended up deciding that he was more concerned about the fact we are each others first partners, and while he loved me, he feels he may be missing out on the young, dating scene, than he was about his feelings for her. 

Fast forward to present, Jenny has been away for work since about October, and while they've seen each other since the fiasco, I've always been there. On Tuesday, he went abroad to visit another work friend, and Jenny is also there. I've just realised that this means they'll be together, without me, in exactly the same sort of scenario that led to our problems last summer. I thought I trusted him, but suddenly I'm so worried about the whole situation (and it probably doesn't help that he hasn't answered my text asking how its going). 

How do I deal with my worries without coming across as overly attached girlfriend-y? Zach has alway put less weight in the original issue with Jenny than I have, but I'm worried and nervous, and I wasn't prepared at all.

Provide a brief overview of the text.
<bot>: Boyfriend is currently on holiday with a girl he has had feelings for, hasn't answered my texts, i'm nervous