I'm not sure what the author's meaning was in asking "is this fair to me". I voted "yes" because I think her girlfriend is taking a difficult step to say "hey, I might not be as ready for commitment as I thought I'd be, I'd rather not hurt you by being unfaithful, distant, etc. -- so we need to take a break before something like that happens." That said you need to face the music: she is already cheating or on her way to cheating on you.