Clearly the guy who wrote the song is expressing his love for his girl, or the girl could be expressing her love for the boy. This is a story of teenage love. This is a story that can be created or made in any relationship.
This song is saying that it is inevitable to have this person to have him/her to love is a privilege. That when or if you were going to break up, it would be a privileged to have your heart broken by him/her. This song is amazing, and I would advise you to listen to it, it will change you're perspective on teenage love.