Basically the song is about her feelings toward her ex's new girlfriend. Shes looking back on their relationship saying that things could have been done so much better ("we both realized it way too late") and how shes maybe feeling some jealously towards the new girl because shes still very much into her ex.
Basically the song is about her feelings toward her ex's new girlfriend. Shes looking back on their relationship saying that things could have been done so much better ("we both realized it way too late") and how shes maybe feeling some jealously towards the new girl because shes still very much into her ex.