At Dean Martin‘s surprise 44th birthday party in Las Vegas, a tipsy Marilyn Monroe put her arms around Frank Sinatra. “Come on, Frankie, let’s make out for the photographers,” a witness recalls her cooing. Frank drew back, escaping the actress’ embrace, and commanded one of his bodyguards to keep an eye on her.

Like with most of the men in her life, Marilyn had a complicated relationship with Ol’ Blue Eyes. Following their divorces from Joe DiMaggio and Ava Gardner, Marilyn and Frank found consolation together and commiserated over their shared troubles with insomnia, loneliness and insecurity. “He has always been very kind to me,” Marilyn told gossip columnist Louella Parsons, when asked about their affair. Indeed, some say that Frank became so intent on saving Marilyn from her demons that he asked her to marry him. “Her beauty and her vulnerability made her seem like a soft little pussycat that needed to be protected,” actress Ruta Lee exclusively told Closer Weekly — in the magazine’s latest issue, on newsstands now — at the Edwards-Lowell Gallery and the Andrew Weiss Gallery Present Marilyn Monroe: 17 Years in the Making opening night.

Marilyn Monroe
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Marilyn and Frank began seeing each other casually in the late 1950s — her maid Lena Pepitone says the star even moved into Frank’s L.A. home briefly to recover after her split from Joe — but their romance really heated up in 1961. “They spent a lot of nights together,” said Jimmy Whiting, a Sinatra friend. “They took bubble baths together.” Out of deference to her ex-husband, who had been a friend, Frank tried to keep the relationship a secret. “He didn’t want Joe to get pissed off,” Jim White, an insider, explained.

That August, Frank and Marilyn hosted friends on the singer’s yacht, but it wasn’t smooth sailing. “[Marilyn] was giving him a hard time…taking a lot of drugs and drinking,” and insider revealed in Sinatra: Behind the Legend by J. Randy Taraborrelli. Frank allegedly threatened to “throw [Marilyn] right off that boat,” but he couldn’t stay angry long. “Marilyn was real dependent on Frank,” explained Jimmy. “She used to say, ‘If I have any problem, there’s only one person I know can help: Frankie.'”

Though he loved her, Frank needed some distance. In February 1962, he announced his engagement to dancer Juliet Prowse — surprising even his closest friends. “I do think it had to do with Marilyn in some way, maybe trying to break from her a little,” Sammy Davis Jr. said. Not surprisingly, Frank’s new romance ended in just six weeks.

Frank Sinatra
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That August, Frank invited Marilyn to Cal-Neva Lodge in Lake Tahoe. “When Frank saw Marilyn, he was alarmed at how depressed she seemed,” Joe Langford, a security guard, recalled. Frank had special meals sent to Marilyn’s room and worried about her well-being. “I think he proposed to her,” manager Milt Ebbins said. “He loved her and he would have done anything to save her.”

But Marilyn couldn’t be saved and died one week later of an apparent overdose. “Frank was in shock for weeks,” said his valet George Jacobs. It grew worse when he arrived at Westwood Memorial Park and discovered that Joe DiMaggio had barred him from her funeral. “I loved her too,” a distraught Frank told a pal. “No one can say I didn’t love her too.”

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