The Summer I Turned Pretty will draw to a close with a third and final season. Details of the upcoming instalment are currently under wraps, however, Gavin Casalegno – aka Jeremiah – has noted that filming will commence "Sometime this year."
We also know that season three is based on Jenny Han's bestselling novel, We'll Always Have Summer, which debuted in 2011. A bonafide page-turner, the final book in the trilogy sealed Belly's fate, concluding her love triangle with the Fisher brothers as she finally chose between them.
So, who does Belly end up? We've got the lowdown on the books, but warning – SPOILERS AHEAD! Stop reading if you want to keep the mystery alive…
What happens in Jenny Han's book We'll Always Have Summer?
We'll Always Have Summer picks up two years after Belly chose Jeremiah, evicting Conrad from her heart. Happy in her relationship with Jeremiah, Belly is finishing her freshman year of college, confident that her love for Conrad is a thing of the past. But, when she hears a rumor that Jeremiah slept with another girl during a brief break in their relationship, she needs some breathing room.
In a Ross and Rachel moment of epic proportions, Jeremiah notes that they were on a break at the time, but Belly can't help but feel betrayed. On the cusp of breaking up, Jeremiah proposes to Belly, and while she's initially hesitant, she accepts.
Returning to Cousins to attend the opening of a memorial garden created in Susannah's memory, Belly and Jeremiah intend to tell their families. Conrad turns up late and struggles with the depth of his feelings for Belly after seeing her for the first time in a while.
Meanwhile, Belly breaks her engagement news to Laurel, who is so disappointed that she forbids the wedding. Caught in a rift with her mom, Belly decides to spend the rest of the summer at Cousins Beach with Jeremiah, where she can plan the wedding in peace.
What she doesn't realize, however, is that Conrad is staying at the beach house too. Convinced that she's over him, Belly moves in, intending to stay out of Conrad's way, which turns out to be impossible.
After offering to drive Belly to mail her wedding invitations, the pair become friends again, with Conrad convincing Laurel to attend Belly's bridal shower. He also notes that Jeremiah and Belly have very different ideas of what they want for their wedding.
As the days pass by, it becomes clear that Belly and Conrad are still tied to one another and with just days until her wedding, Conrad finally confesses his feelings to Belly, explaining that he has always loved her but had to process his mother's death before he could contemplate a relationship with her.
Angered by the revelation, Belly walks away more confused than ever. Determined to let Conrad go she tells Jeremiah what happened. Furious that his brother would try to come between them, Jeremiah confronts Conrad in their mother's memorial garden, telling him that from this day forward, neither he nor Belly will see him again.
On the morning of their wedding, Jeremiah and Belly talk about everything that's happened, but when he asks her if she still loves Conrad, Belly can't deny her feelings. They decided to call off the ceremony and break up.
In the epilogue, Belly herself reveals what happened next. After finishing college and traveling abroad to Spain, she received a letter from Conrad, and they began writing to each other. When they finally reconnect at her college graduation, there's no doubt about it – Conrad's the one for her.
In the final scene we learn that Belly and Conrad have officially tied the knot, taking a detour to the beach before their wedding reception. As she spots Jeremiah with his date, the exes acknowledge one another, revealing that they're now on good terms. As Belly and Conrad head to the beach and jump in the ocean, she reflects on how happy she is to have married the first boy she ever loved.