“I Bet You Think About Me” is a song by the American country music artist Taylor Swift, released on October 7, 2022, as the fourth single from her tenth studio album, *Midnights*. The song is a revenge track where Swift sings from the perspective of a woman who has been wronged by her lover. She implies that he can’t stop thinking about her after their breakup.
The song does not reference a specific person, and as such, “Who” in your question is not tied to a particular individual. The lyrics are written from a fictional perspective and are part of the storytelling that Taylor Swift is known for in her music. The song is a narrative device and not a direct account of Swift’s personal life or relationships.