The song 'BITTERSUITE' by Billie Eilish delves into the complexities of a relationship where the singer struggles with the idea of falling in love. The lyrics depict a sense of longing and conflict, with references to feeling overwhelmed, being cautious, and the bittersweet nature of love. The metaphors of being overseas, dreams, and the color green symbolize distance, unattainability, and envy, adding layers to the emotional turmoil portrayed in the song.