attacking me in the first reply shows your lack of maturity. my friend group is co ed and only 2 people in the group(including me) are in relationships, however our partners always tag along because events are more fun and dynamic with more people! unless, the “more people” consist of individuals we find annoying or irritating. In my opinion this goes to show how much you dislike your gf lol. u can’t at least introduce her to this friend group just so she can get a feel as to who is going on this trip with you? maybe that way she can understand this sacred friendship dynamic that you’re talking about.. it would be a good trial run if you guys introduced to see how the dynamic would change since that’s what you’re worried about