The Summer I Turned Pretty Season 3, Episode 8 explained why Jeremiah Fisher accused Belly Conklin of cheating on him because of something that happened the day after Christmas. A good chunk of the final season of the Amazon Prime Video series mostly centered around the preparations for Jeremiah and Belly's unexpected wedding. While the pair's family was initially against the idea of their marriage due to their age and current college situation, they eventually came around and respected their decision.
However, amid the chaotic wedding preparations, there was a huge elephant in the room, and it all boiled down to Conrad and Belly's lingering feelings for each other (which were clearly apparent and noticed by everyone around them, including Jeremiah). It was a ticking time bomb of a situation, especially after Season 3, Episode 7 culminated with Conrad's gut-wrenching confession of his real feelings toward Belly two days before her wedding with Jeremiah (which left Belly conflicted about her feelings over the two brothers).
It's worth noting that the wedding wasn't supposed to happen this early because Jeremiah appeared to have panicked after Belly broke up with him due to his cheating scandal with Lacie Barone. As a result, he made a last-ditch effort to be with Belly by proposing to her, leading to the wedding they were unprepared for in the first place.
Did Belly Cheat on Jeremiah With Conrad?
While The Summer I Turned Pretty Season 3 confirmed that Jeremiah cheated on Belly with Lacie Barone during spring break in Cabo, Belly also had a secret that she has yet to reveal to Jeremiah: she spent Christmas with Conrad at the summerhouse in Cousins.
During that specific Christmas, the spark between Belly and Conrad was reignited. They laughed, bonded, and looked at each other the same way when they fell in love for the first time. While nothing happened between them, it was clear that something deep down in Belly changed and had something to do with her real feelings for Conrad.
Belly chose to keep this a secret for the longest time, but the latest episode confirmed that Jeremiah knew about Belly and Conrad's Christmas in Cousins. It changed everything since knowing what happened between Belly and Conrad during Christmas prompted Jeremiah to pick a fight with her before spring break, leading to his cheating scandal in Cabo (it's quite messed up).
While Belly did not physically cheat with Jeremiah, one would argue that she emotionally cheated on her fiancé because she chose to keep it a secret:
Jeremiah: "I know about Christmas. I know you two were together."
Belly: "Jere, nothing... nothing happened. I-I would have told you. I-I swear that we didn’t..."
Jeremiah: "I know, I know you didn’t sleep together, okay? But something happened, something bigger than that. You started to love him again. The two of you in the house all summer. And f*ck you both for making me think it was all in my head."
The final nail in the coffin is that Belly's time with Conrad during Christmas led her to start loving him again, which started the downfall of Belly and Jeremiah's relationship.
However, Jeremiah was also in the wrong because he revealed that he used Belly and Conrad's alone time during Christmas as an excuse to pick a fight, leading to him sleeping with Lacie during spring break. It goes without saying that one misstep cannot mend another, further proving that Jeremiah dug his own grave.
What Happened to Jeremiah & Belly's Wedding?
After several brutal, gut-wrenching revelations mere minutes before the wedding, Jeremiah and Belly's wedding didn't go through. There were a myriad of reasons why.
Belly chose to be honest with Jeremiah about the part of her that will always love Conrad, noting, "I'll always have him in my heart."
"I think I’ll always love him a little. I’ll always have him in my heart. But he’s not the one that I choose. I choose you. I choose us."
However, Jeremiah said this was never enough because he didn’t want a part of her; he wanted all of her. It will never work.
In fact, Jeremiah pointed out that Belly could've said no when he proposed to her, but she still chose to push forward instead. He thought that Belly was ready to forget Conrad by saying yes, but this wasn't the case because she answered that she still loved him despite everything.
It was heartbreaking for Jeremiah to witness how much he loved Belly, but he would never be enough. He told her that she couldn't marry him to erase Conrad, and this served as the last straw in allowing Belly to let go of Jeremiah, ultimately ending their chances of being together forever.
Jeremiah admitted that he doesn't know how not to love her. Belly knew that Jere would still marry her even after everything, but she knew it was selfish to do so because she knew the truth: she was still in love with Conrad.
