New biography reveals why Jackie Kennedy burned secretive old letters and photos right before she died

In a new biography about Jackie Kennedy, the author reveals new information about the inner workings of the former First Lady's personal life - including why she used to burn old letters and pictures.

Jacqueline Kennedy Onassis was, and is still, beloved by many, known widely for her philanthropic spirit and her impeccable taste in fashion, which has inspired even the likes of Kate Middleton. Of course, her presence became known widely on account of her marriage to former late president John F. Kennedy. 

It is not a secret, however, that John was reportedly unfaithful to Jackie during their marriage - John allegedly had affairs with other several women, including the likes of the illustrious Marilyn Monroe. 

In a new biography about the former First Lady titled 'Jackie: Public, Private, Secret,' by J. Randy Taraborrelli, the author reveals in an excerpt that Jackie received a love letter around Valentine's Day toward the end of her life from her former lover, architect Jack Warnecke.

In an excerpt from the book obtained by People, this note from Jack led to a reunion at her apartment - which occurred just several months before her death on May 19, 1994, from non-Hodgkin lymphoma.

Ironically, Jackie had fallen in love with Jack just three decades earlier when John was assassinated - he was the architect who Jackie commissioned to design John's gravestone, which can now be seen in Arlington National Cemetery in Virginia.

Jack shared this information with the author of the biography, but had just one condition - he was not allowed to share the exclusive information until a decade after he died. Jack died in 2010 - and now J. Randy is sharing the story of their love affair. 

The excerpt shared with People about their relationship reads as follows: "It was in the middle of May 1964 when Jack Warnecke called to ask her out. “On a date?” she asked. “Because I don’t date, Jack, and I never will again,” she said. No, Jack told her, it wasn’t a date. It was just dinner. That night, he showed up at her door with flowers. “But, Jack, I didn’t say yes,” she told him, annoyed. “But you didn’t say no,” he said with a smile. “That’s when it started between us,” Jack Warnecke recalled."

Eventually, their relationship came to a tumultuous end, and Jackie entered a marriage with Aristotle Onassis, which lasted just seven years until he died at 69. 

Jackie and Jack later reconnected, and Jackie invited him over to her apartment, where they burned each other's old letters in the fireplace. 

The excerpt also reads: "In [our] 1998 interview, Jack said, "As I took my seat, Jackie handed me a stack of envelopes neatly tied together with yarn. My presence that evening was part of a ritual. Every night that week, she was inviting a trusted friend or family member to her home to take part in it."

Jackie untied the yarn and took a letter from the stack. She read it before placing it into the fire. He recalled, "There were letters from Jackie’s children, John and Caroline ... There were also letters from Jack Kennedy, Aristotle Onassis, her father, Jack Bouvier and even a few from me.""