Am I in the wrong here?

I have been dating this girl I want to marry for the past 4 years. We are both believing muslims. So heres when the problem comes to play, every year I take a trip with my friends(all muslim guys) to like LA. We stay in my best freinds sisters house, who is married and has a kid and also are muslims. My girlfriend doesnt approve of it because I have never been on a trip with her, and also because there would be a woman in the house that I would be staying in. I havnt been on a trip with her because, ofcourse my parents woudnt approve, and you know how arab parents are. My parents are fine with me going with my friends. I tell her once we get our nikah done we will go wherever we want. But thats not good enough for her and she says if I go well be done. Am I wrong if I go or is she wrong for doing that? I look forward to your answers inshallah.