Is it just me being over sensitive?

So my boyfriend has a squad of college friends. I’ve always doubted one of the girls in the group, and recently she has been asking out my boyfriend and another guy for outdoor activities but no one else, not all the other girls in the group, just the two taken guys in the squad. Almost weekly the three of them go to islands or go biking together, when I’ve long told my boyfriend that I’d love to go out to the sea and to the islands but till now the two of us have never gotten the chance to do so... while she has the privilege??

I’ve been really sad the past few days and couldn’t sleep well, my friend said the line is being crossed here but idk if it’s us who are over sensitive and protective, what do you guys think?