With all those promises that The Summer I Turned Pretty would be different from the books, it should come as no surprise that even the cast didn't know how the show would end while filming the final season. During an exclusive interview with Us Weekly, Sean Kaufman revealed how much he knew about where his character Steven's story was going in season 3. "It was definitely open-ended. I had no idea. And [creator] Jenny [Han] likes keeping us all on our toes, which is always fun," Kaufman, 25, teased. "I was just kind of along for the journey.