I like how Dave emphasizes that angry and controlling reactions are NOT the way to go here, regardless of how the LR is feeling. Of course open honest communication and maybe some counseling can be very helpful. His girlfriend has an opportunity to clear the air here and I hope she takes it. But I have  two minor insights: one, I know at least two men, exes, who stayed friends with their exes for years hoping it would turn back into love. Two: maturity. Do these people know themselves? Have they been around a time or two and know what makes life worthwhile? Or are they still forming who they are through their friendships and experiences? If so- maybe she doesn't know what she wants and the LR has every right to question this situation.