P.S. I still Love You by Jenny Han

Lara Jean didn’t expect to really fall for Peter.

They were just pretending. Until they weren’t. And now Lara Jean has to learn what it's like to be in a real relationship and not just a make-believe one.

But when another boy from her past returns to her life, Lara Jean’s feelings for him suddenly return too. Can a girl be in love with two boys at once?

In this charming and heartfelt sequel to the New York Times bestseller To All the Boys I've Loved Before, Lara Jean is about to find out that falling in love is the easy part.
 
- Goodreads Summary