LOS ANGELES (Reuters) - Pop princess Britney Spears has admitted that she had sex with former boyfriend Justin Timberlake despite once vowing to remain a virgin until she wed.

In the upcoming issue of W magazine, Spears details her relationship with Timberlake, the most-watched music industry romance since Courtney Love and Kurt Cobain.

"The most painful thing I have ever experienced was that breakup," Spears told W. "We were together so long and I had this vision. You think you're going to spend the rest of your life together. Where I come from, the woman is the homemaker, and that's how I was brought up -- you cook for your kids."

The 21-year-old Spears, whose stratospheric rise from Mouseketeer to pop megastar mirrored Timberlake's success, revealed that she had sex with the 'N Sync boy band singer because she believed they would marry someday.

"I've only slept with one person my whole life," she said. "It was two years into my relationship with Justin, and I thought he was the one. But I was wrong!"

Spears, now cutting an image-shifting, comeback album after an 18-month hiatus, said she now realizes "I need my single time" to learn to "be self loving."

"I know it sounds cliche and cheesy, but I really believe that if it's meant to be, it's meant to be," she said.

For now, Spears said, she's hunting far afield for a new beau -- especially in Australia and Spain where men are less "fuddy duddy."

As for reports linking Spears to Irish heart throb Colin Farrell, she said: "Yes I kissed him. Of course I did! He's the cutest, hottest thing in the world -- wooh! He's such a bad boy. But it was nothing serious."

The kiss left her with a "craving" for more of the same. "I haven't had a boy in a really long time ... just a kiss, man. Just a kiss would be nice."

my dreams are shattered

what a crock, i don't get the credit i deserve! I deflowered that lying whore back in the 7th grade.

Mr. Timberlake how did my lunch taste? ahahaha

Could Playboy pics be far behind?

you cook for your kids then you drink.

Why am I still a virgin?

then you drink, then you have sex. Episodic sequence. Poor bastard.

When you read her quotes, don't you get the feeling she's totally screwed up mentally? Gosh, I'd trade fame for a normal life any day. She's kind of whacko.