Maybe there's a switch of speaker in the last section, the tone is so different. It's the old boyfriend she still loves reclaiming her. He had lost interest in the relationship, but now is re-invigorated by the spirit of competition with his usurper. The relationship between the two men is subtly homoerotic: "I kissed your lips... It made me think about him"; "You didn't think that I could sit around and let him go."
Maybe there's a switch of speaker in the last section, the tone is so different. It's the old boyfriend she still loves reclaiming her. He had lost interest in the relationship, but now is re-invigorated by the spirit of competition with his usurper. The relationship between the two men is subtly homoerotic: "I kissed your lips... It made me think about him"; "You didn't think that I could sit around and let him go."