Oops! I did it at last!

That’s what Britney Spears might be singing in the wake of an explosive report claiming the pop tart has been lying when she insists she’s never had sex with long-term boyfriend Justin Timberlake of *NSYNC.

The 21-year-old sizzler is the world’s most famous self-proclaimed virgin — a title inherited from the now-married Brooke Shields.

But privately Britney has confessed to pals: “Justin and I have great sex,” according to the report.

A London newspaper — which headlined its story “Britney lets out bedroom secret” — insists that “gorgeous pop star Britney Spears is NOT a virgin.”

The nubile singing sensation was overheard at an awards bash bragging about her love life with Justin, according to the article.

“We’re just like any other couple — but I don’t like talking about it publicly,” she reportedly confided.

A bystander said: “I was stunned. She’s always told everyone she was a virgin. But nature will take its course.”

Beautiful Britney, who bounces around the stage in flesh-flaunting outfits, has always maintained she does not believe in sex before marriage.

Britney is a natural-born brunette who bleached her hair blonde.

But last year Britney and Justin purchased a Los Angeles love nest and shared a luxury suite at the Intercontinental Hotel in Rio de Janeiro.

Justin even bought Britney a pair of suggestive silver handcuffs for her recent birthday.

“It’s seems like something happened and Britney couldn’t wait to tell someone,” a pal disclosed.

“Justin’s one of the luckiest guys in the world.”