Have you heard the dirtiest, nastiest, Naziest rumor about Sandra Bullock and Jesse James? It involves anal sex, the barrel of a shotgun, a Hitler poop-stache, and a video camera. It's a Freudian nightmare come to life. It's a myth.

And it's a good, potent myth, right up there with Richard Gere's gerbils and Lady Gaga's penis. The ludicrous tale—which Bullock denies—goes something like this:

Jesse James has a sex tape of her engaged in more than simply sex. [...] Bullock was penetrated anally by a shotgun, wore a mustache made of human excrement, and had sex with Nazi paraphernalia scattered around the room.

Then Michelle Bombshell gets a cup and Eva Braun starts puking. "What's the name of your act?" a man named Dirty Sanchez asks. "The Aristocrats!" they reply.

The story is the perfect storm of visceral revulsion (poop! face!), exaggerated danger (gun! penetration!), offensive politics, and impolite humor. (Admit it: the Hitler poop-stache made you laugh.) The promise of a sex tape offers an evidentiary bluff and a familiar medium for Hollywood scandal. It borrows imagery from believable rumors about Jesse's ties to neo-Nazis. And it coincides with rumors about sex tapes and "secrets."

The poop-stache story even has well-known source: Ian Halperin, the outrageous and prolific unauthorized biographer who "eerily predicted" Michael Jackson's death—then staked his reputation on the myth that Brangelina were breaking up, and wrote an embarrassingly error-ridden book about the duo. Halperin's record—like each of the rumors he starts—mixes the believable with tabloidism that defies belief. When it comes to facts, his results vary widely. When it comes to juiciness, he knocks it out of the park every time.

Which may be why Bullock finally broke her silence to respond to Halperin's allegation: "There is no sex tape," she told People. It's an outrageous, tawdry, humiliating rumor. And some element of it hit close enough to home to get under Sandy's skin. My guess is it's the implication that Sandra is into Nazi stuff, too—that's the part she's afraid we'll believe, and the part I'm most curious to see her address. [h/t atlasfugged, image via Getty]