Like what insight79 said, I agreed with those he wrote. But I believe this song is a guy's thought song. The guy always accused the girl for being unfaithful. But i strongly feel that, the guy had deliberately accused her because he has got some reasons which made him thought that he would not be able to be with her. So in my opinion, this song is actually a guy's thought on how the girl had suffered in the relationship. He felt very bad about it because it was his fault and he knew it. Therefore, he was guilty and has been pondering about her singing the song, about their story.
Like what insight79 said, I agreed with those he wrote. But I believe this song is a guy's thought song. The guy always accused the girl for being unfaithful. But i strongly feel that, the guy had deliberately accused her because he has got some reasons which made him thought that he would not be able to be with her. So in my opinion, this song is actually a guy's thought on how the girl had suffered in the relationship. He felt very bad about it because it was his fault and he knew it. Therefore, he was guilty and has been pondering about her singing the song, about their story.