What should i do? any advice would be great folks?

Me and my girlfriend have been together for a year now, and things are generally good, I love her to death and am always looking out for her. For the longest time, since we started going out over last summer we used to play Xbox live together, and this one dude who she said was really creepy one day and then her friend another day. She doesn't know this other kid, he lives in new Hampshire and we live in new York. Apparently they flirt on Xbox, thanks to a trusted friend, and he added her on Facebook, she accepts every request on that thing. She has added so many people she doesn't know, and a few of them talk to her and vice versa. It really bugs me and makes me feel uncomfortable. So now we are in present time and she and this kid, Colby, text and use oovoo together on occasion, I already found out they flirt via texting and I don't know about oovoo. She said she has the slightest of feelings for him as more than a friend and I am so confused because she hasn't met this person and why she talks to them(people she doesn't know) I don't know. I don't know how I should honestly approach this, I don't want to break up with her because she feels the same way for me as I her.