I think this song is about someone she has known for a very long period of her life. As a friend and as a lover. No matter what happens between them, through their fights, differences and issues, they always end up being back together again because, well. They belong together. Reminds me of me and my best friend, we are so much more then best friends, and we used to fight all the time. The first verse is an exact replay of what he did one night after our biggest fight. And the rest of the song is just me and him to a T. I would be lost without him and I know he would be destroyed without me. I guess we just love each other.