Where did he hide them?

In Jennifer Lopez’s new documentary, The Greatest Love Story Never Told, the “On the Floor” singer — who reunited with ex Ben Affleck in 2021 after breaking off their 2002 engagement — details the duo’s famous romance, which the actor documented in a series of love letters

Ben Affleck and Jennifer Lopez tied the knot in 2022.

In one part of the film, Lopez revealed how Affleck had kept all their written communication to one another over the years despite his 2005-2018 marriage to ex Jennifer Garner, whom he shares kids Violet, 18, Seraphina, 15, and Samuel, 11.

“This book is a book Ben gave me on our first Christmas back together. It is every letter and every email that we wrote to each other from 20 years ago and today,” the actress shared of the Good Will Hunting star, whom she tied the knot with in 2022.

One note read, “The Greatest Love Story Never Told by Jennifer Lopez and Ben Affleck 2001-2010…and counting…”

Additionally, the documentary detailed how Lopez passed on these personal love notes to songwriters and musicians to create her new album This Is Me… Now.

Ben Affleck and Jennifer Lopez were previously engaged in 2002 before they called it off.

In the footage, Affleck shared how he was taken aback when he learned she had shown the letters to others.

“I was like, ‘You’ve been showing all the musicians all these letters?’” he recalled. “And they were like, ‘Yeah, we call you Pen Affleck.’ And I was like, ‘Oh my God.’”

Affleck also expressed his opinion on how much of their private life was being shared in the movie.

“Jen was really inspired by this experience, which is how artists do their work,” he explained. “They get inspired by their personal life, it moves you. I know as a writer and director I certainly do the same things.”

Ben Affleck and Jennifer Garner were married from 2005-2018.

“Things that are private I always felt are sacred and special because, in part, they’re private. So this was something of an adjustment for me,” he admitted.

As OK! previously reported, a source spilled that Affleck doesn’t understand why his wife would spend upwards of $20 million of her own money to share their personal life.

Ben Affleck and Jennifer Lopez share three kids.

“Ben has gotten very good at biting his tongue, but it’s known that he’s not happy at all about J.Lo’s endless need for attention,” they dished.

“Ben loves J.Lo dearly, and he knew what he was getting into, to an extent,” the insider said of his participation in the documentary.

“But his fear is that by putting so much of herself out there, J.Lo’s just opening them up to way too much public scrutiny, and that hasn’t helped their relationship historically — far from it,” they added, referencing how the du was originally engaged in 2002 but broke it off right before the wedding.