Dating George Clooney isn't always fireworks and fancy Italian villas. The Oscar-winning two-time Sexiest Man Alive reveals to the New Yorker how he tried to find out who was responsible for leaving an offensive message warning him to drop-kick dewy girlfriend Sarah Larson -- or else.

The voice mail, which was left on George's private line by someone with "a calm, middle-aged male voice," cautions him, "Dude, your friends asked me to give you a message: Dump the b---- before you're sorry!"

Clooney, who's been squiring the toothy brunette since August of last year and brought her along to the Oscars, the first girlfriend he's bestowed with the honor, dismisses the idea that one of his pals was playing a practical joke.

"It's not a prank," he tells the magazine. "None of my friends would do that."

Happily, the nasty heads-up had the opposite effect intended: It brought out the star's protective side.

He had his "police-officer driver" attempt to track down the caller, but the investigation has only gotten as far as a prepaid cell phone. Now, they're looking to see if the guy purchased it with a credit card.

"There are certain laws that, you know, that are applicable," Clooney good-naturedly explains to the interviewer, before asking Larson, "It's wild, isn't it? Isn't that interesting?"

Her unenthusiastic response: "Yeah."

Larson, who heard the message for the first time when the actor played it for the magazine, was surprised ("Before you're sorry?" she repeated). And she says that, since becoming the actor's arm candy, she's been subjected to many unkind comments.

George Clooney and Sarah Larson at the Universal Pictures Premiere of "Leatherheads"

"They say that I'm a stripper. There's a ton of stuff about that. I've never been a stripper," fumes the former waitress and "Fear Factor" winner (she might want to keep things in perspective by reminding herself, "Holy crap, I'm dating George Freakin' Clooney -- life is pretty damn good"). "You know, just because I'm from Las Vegas, I must be a stripper. Because I'm a cocktail server, that means I'm an escort."

Old photos recently surfaced showing Larson getting frisky with an unidentified man, various galpals and a glossy magazine, which she's seen licking while sporting a bikini.

Her past is also popping up in the British tabloids, courtesy of her ungentlemanly ex-boyfriend, whose remembrances of flings past have an air of Cinemax after dark.

"She made up special love potions and rubbed them into every part of my body. I was powerless to resist," a blabby fella named Tommy McKaughan asserts to Britain's News of the World. "I know George will be no different. He'll be totally entranced."

Tommy, who claims he dated Larson for six years, describes her as "a total hippy at heart, heavily into all the spiritual, mystic stuff -- crystals, tarot cards, healing."

He continues to lay it on thick as he reminisces, "And along with her witch-like charms she's a brilliant fun girl with NO inhibitions. She loves nothing more than getting NAKED in a forest. Some of our wildest nights were out in the woods romping in the grass and [in tents] ... Sarah would bring her crystals and ease away my aches and pains with healing ceremonies."

He also dredges up a memory Larson would probably like to forget: "She learned how to perform the classical Indian dance Orissi. George will love it. She'd play her bongos, put some oriental music on and start these incredibly sexy moves like belly dancing."

On the plus side, McKaughan is unlikely to leave a spiteful message about Larson for Clooney.

"She's an amazing girl and deserves nothing but the best," he tells the tab. "And if anyone can tame George, Sarah can."

Next: Paul Plays Field, Pens Moving Tribute to Linda