I think this song means that shes in love with a guy hu is also her best friend and because shes his best friend he confides in her that hes in love with someone else and that hurts her and she says how great it would be if he new how she felt and then fell in love with her too. She also compares it to movies and I think she says that in movies every movie its the same thing girl loves guy friend, guy friend loves difrent girl and finally guyfriend starts to love the first girl but in real life its not happening and she wishes it would.