In Taylor Swift's "august," the narrator loves the fictional 17-year-old boy James.
James is one point of the love triangle developed across three Folklore songs. "August" presents the perspective of the unnamed girl involved in a brief summer romance with him. "Betty" presents James's perspective, while "Cardigan" centers on Betty's viewpoint.
The story is fictional rather than a direct account of a documented relationship in Swift's life. James is already connected to Betty, and the summer relationship described in "august" ends when he returns to his former lover. That makes the song a story of unrequited or temporary love rather than a lasting partnership.
A common mix-up is calling the narrator Augustine or Augusta. Swift said she imagined possible names for the character, but the song itself leaves her unnamed. James, by contrast, is explicitly identified within the trilogy's narrative.