The Summer I Turned Pretty's final season surprised fans due to the handful of cheating story lines - some of which weren't even in Jenny Han's book series. Prime Video's hit series, which debuted in June 2022, is based on a book series of the same name by showrunner Han. The Summer I Turned Pretty focuses on Belly (Lola Tung) who gets caught up in a love triangle where, after exploring her feelings for Conrad (Christopher Briney), she starts to reconsider whether his brother, Jeremiah (Gavin Casalegno), is her perfect match.