Here's a bit of background...

I met a girl that was going to Australia for 6 months a few weeks after we met, so I made an effort to see her. The date went well, but she didn't want to go to the backseat of her car.... I was fine with that, but she told me that it was because she wanted a serious relationship with me.

Fast forward 6 months, she's back, but now she's with someone. (The guy is still over there, traveling). I dated other girls in that time frame too, but nothing ever became serious enough for me to tell her. Also, I was never under an obligation to her since we never decided to be in a committed relationship before leaving.

However, I am hurt that she didn't tell me before seeing me in person and effectively lied to me. I'm not sure if I should remain friends with her (and I don't think I'd want to date her should she become single since I would not like any girlfriend of mine going out to see an old flame no matter how much I trust her judgment).