I'll start from beginning.
I was partying and getting laid almost every week with different girl. Now in one party i met someone. Lets call her Gwen. And she is so much like me, my style etc. When we went to bed she said that she doesn't do one night stands. At this point I wanted to get her more and more. So I got.. I thought that now she will beout of my mind but no. We were together for about one month. Yesterday she told me that she wants to be free. That we can have free relationship. Like we can fuck but she'll see other man. She told that she likes me a lot but she doesn't want to be tied to one man.
But I can not be with her if I know that she is having fun with others. So I said that it doesn't work for me.
I want her back but don't know if it's good idea to try to do that.

Give me some advice here. What should I do.