In "P.S. I Love You," the high schooler, played by Lana Condor, thinks she's fully committed to her now-official boyfriend Peter Kavinsky (Noah Centineo) but then she becomes confused when she realizes she also has feelings for John Ambrose McClaren (Jordan Fisher), a friend who re-enters her life after receiving one of her old love letters.
Condor told Fox News she loved having Fisher join the cast.
"Jordan is such an incredibly confident man, and so he had huge shoes to fill I think like in terms of like going up against Noah," she said. "[Jordan] fit in immediately and he's just the perfect addition to our family."
"We had a lot of conversations about the first movie and we had a lot of conversations about the book., 'P.S. I Still Love You,' and what he thought John Ambrose was," Condor added.
The 23-year-old actress also gushed about working with Centineo again, who was dubbed the "Internet's boyfriend" after the success of the first Netflix movie. "He's so good at delivering these incredibly romantic lines and like very, very believable," she laughed.
Condor's life completely changed after the series became one of the top-watched movies on the streaming platform in 2018, which made saying goodbye to Lara Jean particularly difficult.
The cast shot the second and third movie — "To All the Boys: Always and Forever, Lara Jean" — back-to-back and Condor admitted she's still processing it.
"I spent the whole [last] day kind of like denying it," she confessed. "So I was in a pretty bad mood because I was just like, I don't want to say goodbye."
"[The character] changed my life and she's been such a huge part of my life that it just gets you and hurts really badly," Condor described. "I'm just so thankful for [Lara Jean]."
"To All the Boys: P.S. I Still Love You" is now available to stream on Netflix.