A girl wrote me on fb because she saw a post of mine in a group of "university books market" in which I wrote that I was searching for a book. She thought I was selling it and wanted me to buy it (she said that she misread my message); then we started talking about textbooks, their prices, about university, exames, and about a person that we both know. A day and a half later (today) I told her a joke about something she wrote on the group and she laughed. Then I told her if she wanted to get to know each other face-to-face and not on fb in front of a coffee the day after tomorrow. She replied almost 2 hours later (she would always answer immediatly), I quote, "Look... Actually I am seeing somebody in this period and I don't want to create misunderstandigs to him... But thanks for the invitation..."

I haven't replied to her. A friend of mine (who has quite a success with woman) told me that A girl wrote me on fb because she saw a post of mine in a group of "university books market" in which I wrote that I was searching for a book. She thought I was selling it and wanted me to buy it (she said that she misread my message); then we started talking about textbooks, their prices, about university, exames, and about a person that we both know. A day and a half later (today) I told her a joke about something she wrote on the group and she laughed. Then I told her if she wanted to get to know each other face-to-face and not on fb in front of a coffe the day after tomorrow. She replied almost 2 hours later (she would always answer immediatly), I quote, "Look... Actually I am seeing somebody in this period and I don't want to create misunderstandigs to him... But thanks for the invitation..." I haven't replyed to her. A friend of mine (who usually has quite a success with women) told me that since we have spoken only on fb she could be quite interested but not enough to accept immediatly my invitation. He also told me that I should have insisted or maybe that should try again these days (this happend 5 days ago) saying something like "Hey, are you still seeing this guy? :) In any case we should go out for a coffee, it’s going to be nice to get to know you better, if nothing else, we can just be friends.” This last sentence is suggested by the PUA David De Angelo.

So what do you think? Should I write her again? Or should I simply give up, because she doesn't want to go out in any case?