From experience, traveling creates a high with the reality that it's short lived because someone's leaving soon and relationships tend to move very quickly through a lot of the phases. It makes you feel a huge rush of the honeymoon period, everything is good, there's no bad, sex is always great but then you split and you're left with that lingering memory of that incredible experience. You were literally swept off your feet for a couple days. I've been in this exact experience with a girl who quite literally wanted to advance the relationship, but the reality is that it was a fun couple nights, that's all it was, you have to accept it for what it was and move onto mundane existence.