Friend is heartbroken and confused!

[curiouss]

I am confused also. A close friend of mine has been going out this guy for the last past 8 months. Recently she told her bf that he was the first one she ever had in her life, she's 21. She told me that he was shocked, and not in a good way. Within the last week, he just abandoned her without any reason. The only reason we can come up with, is that he wasn't too fond of being her first and only boyfriend for some reason. The situation is really confusing to me, because I thought it would be flattering to him that he was her first boyfriend at 21. I feel really sorry for her and I don't know what to do.