Raise a Valentine’s Day rose to Phyllis McGuire today, on her 88th birthday.

An American classic and one of the last links to the Rat Pack era, McGuire dropped out of public sight almost a decade ago, just as she vowed.

The last time I saw her was at a “Keep Memory Alive” benefit for Alzheimers, one of the biggest galas on the social scene. My wife, Cara, and I were walking in when Phyllis joined us.

In a city illuminated by its famous neon, Phyllis stood out in her signature Harry Winston diamonds and haute couture.

Ever elegant, she made it clear that night that her days on the red carpet were dwindling.

“The day I need a cane or crutches is when no one will see me at these events,” she said.

She became the last surviving member of the famed 1950s singing trio, the McGuire Sisters, on Dec. 28 when Christine, the oldest, died at her Las Vegas home. She was 92. Middle sister Dorothy died in 2012, at the age of 84.

The wholesome trio from Middletown, Ohio – their mother was a minister -- stormed to the top of the pop charts with No. 1 hits “Sincerely” and “Sugartime.” Their rise to stardom began in 1952 on “Arthur Godfrey’s Talent Scouts” and they became fixtures on his shows over a seven-year period and performed for five presidents.

Few Las Vegas entertainers led a more colorful life than Phyllis, who preferred men with a history of scandal. She reportedly met Chicago mob boss Sam Giancana at the Desert Inn, where the McGuire Sisters were headlining. They hit it off while gambling. He was 52 and she was in her late 20s.

That relationship reportedly cooled when another suitor, oilman “Tiger Mike” Davis, put a gun to Giancana’s head and told him stay away from McGuire.

Before he was “Tiger Mike,” the Texas wildcat oil driller, Davis was a pugnacious chauffeur in Denver, where he married one of his clients, Helen Bonfils, the publisher of the Denver Post, in 1959. Bonfils, who had a penchant for fur, big hats, and Broadway, was 69. Davis, 28, was soon having an affair with McGuire. The Bonfils-Davis marriage ended after 12 years, with Davis walking away with $1.3 million in promissory notes, a mansion and $50,000 in cash. With his small fortune he started his oil company.

In the early 1990s, McGuire began a romance with rough-around-the-edges Bob Stupak, a high-stakes poker player and entrepreneur who created the Stratosphere.

They had broken up a year before the May 1996 opening of the Stratosphere. On March 31, 1995, Stupak and his son, Nevada, then 19, survived a near-fatal motorcycle accident on Rancho Road.

Bob Stupak was in a coma for nearly two weeks with massive head injuries and broken bones. His son sued the driver of the automobile, alleging neck, head, back and leg injuries as well as mental stress and anxiety.

I interviewed Nevada this week in the lobby of the Regency Towers. He said McGuire opened her home to his father and “nursed him back to health.”

During that time McGuire also allowed Nevada Stupak and his sister, Nicole to stay at her Rancho Circle home, which was always under 24-hour armed security.

After Stupak recovered, he and McGuire underwent through another split. This time Stupak apologized with 1,001 red roses

“My dad had been caught in an indiscretion,” he said, and to make up for it “he essentially decided to empty out every flower shop in Vegas of roses and they were bringing them in by the semi-trucks.”

Stupak had a press release sent out announcing the jaw-dropping make-up gesture.

When the Stratosphere opened three months later, in May, 1996, McGuire was on Stupak’s arm, with a video crew close behind.

“It was a true romance and he always had feelings for her,” said Stupak’s son.