Pang, a former assistant to the married couple, is detailing her 18-month romance with the "Imagine" singer in a new documentary titled "The Lost Weekend: A Love Story." John Lennon and Yoko Ono’s marriage wasn’t always peace and love. From late 1973 through 1974, Lennon embarked on his "Lost Weekend" in Los Angeles while being separated from his wife.

Ono had banished the singer/songwriter from their home after he had had "loud, raucous sex" with another woman at a party. While Lennon was eager to return to Ono, she was wary about him coming home. That’s when she got by with a little help from an unlikely Beatle.

BEATLE JOHN LENNON, YOKO ONO RECEIVED GRIM PREDICTION BEFORE LEGEND'S MURDER: FRIEND Paul McCartney (right) gave John Lennon (center) advice on how to win back his wife Yoko Ono (left). (Michael Webb/Keystone/Getty Images) "There was a time when Sir Paul McCartney offered Yoko his willingness to speak to John in Los Angeles about the separation," the couple’s pal, Elliot Mintz, told Fox News Digital. "She seemed grateful for that invitation.

" The former Los Angeles radio and TV announcer, who met the couple in the early ‘70s, has written a new memoir, "We All Shine On: John, Yoko, & Me," with the blessing of their son, Sean Lennon. In the book, he describes how McCartney gave a heartbroken Lennon sound advice on how to win back his love. "Paul came out here, he had a meeting with John," said Mintz.

"His advice to him was, ‘You can’t just say that you�.