The Summer I Turned Pretty is coming to an end but what has been teased about the conclusion - including who Belly ultimately chooses? Based on Jenny Han's book trilogy, Prime Video's hit series follows a love triangle between Belly (Lola Tung) and brothers Conrad (Christopher Briney) and Jeremiah (Gavin Casalegno). The Summer I Turned Pretty served as the inspiration for season 1 while It's Not Summer Without You was the basis for season 2. Viewers were expecting season 3 to rely heavily on the events in Han's third and final book in the series: We'll Always Have Summer.