I agree with your therapist, but at the same time, it would be fun to go. I don't know your background that may have triggered this sleeping alone behavior, but I don't find it to be a real issue. It sounds like your g/f is projecting her values on you rather than excepting you (and your quirks) just as you are without trying to change you. I think that when in a relationship, no one should be trying to change the other person. Hey...I've been married for 16 years and my wife loves to sleep on the couch. I'm like your g/f and believe that couples should sleep together, but you know what...I don't really care where she sleeps anymore. As long as she sleeps (she has a sleeping disorder). So I just except it, love her, and look over these little quirks just as she looks over mine (especially my depression).

I hope you have fun during this trip, regardless if its with your g/f or not