Britney Spears exchanged a smooch with a college student during a racy game of topless truth or dare, Us Weekly reports.

College student Matt Encinias, 21, an extra on Spears' latest video, told the magazine that Spears invited him and some of the other video extras to a late-night private pool party at the Standard Hotel in Los Angeles.

Spears, 25, who reportedly was drinking with the gang, then encouraged everyone to play topless truth or dare ... and Encinias ended up locking lips with the pop star.

"Britney was the first one to undress, and then everyone else followed. I turned around and saw that she was topless and she had fake tattoos of flowers on her nipples from the shoot," he said. "I was told all she wanted to do that night was kiss a boy, and that's what she did. Mission accomplished."

Click here for pics and for the Us Weekly report

Although Spears was expecting her two young sons to be dropped off at her Beverly Hills home at noon (as per her custody arrangement with their father, Kevin Federline), the singer had arranged to have the pool reopened at 2 a.m. for the exclusive use of her group, which included then-assistant Shannon Funk and some hand-picked male extras from her video shoot.

“I was dared to get naked and get out of the pool and walk as though I was on a catwalk in a fashion show,” said Encinias.

Meanwhile, Spears crashed her black Mercedes into a parked station wagon in Los Angeles Monday, and then told the paparazzi, "I'm a brainiac!" the New York Post's Page Six gossip column reports.

In another blow for Britney, her new fragrance, Believe, will soon come out with someone else's tighter body on the packaging.

Spears walked out of a shoot for the perfume's ads before decent shots were taken. But that hasn't stopped Elizabeth Arden's marketing campaign for the scent.

"She looked amazing, but she left the shoot three times in a state of distress before driving away for good," the Page Six source said. "They had decent shots of her face, but not her body, so the art director made the stylist — a cute girl name Kylie Cavaco — get in Britney's clothes and pose.

"They are superimposing Britney's head on Kylie's body. Kylie has the body Brit used to have, not the one she has now."

In late April, after shaving her head and attacking a photographer's car with an umbrella, Spears did manage to get through a cover shoot for Allure's September issue.

Insiders told Page Six, "She did the cover shoot and was fabulous. She did everything they needed her to do. Everyone was saying how professional she was — but then, she never showed up for her interviews."

Women's Wear Daily reported that Spears skipped four interviews with Allure writer Judith Newman. What was originally meant as a "comeback" piece set around the time of her album release was transformed, according to the Page Six source, into a "firsthand account about every time the reporter tried in vain to do the interview."

A similar situation occurred at Spears' OK! magazine shoot last month — she reportedly walked off with $14,496 worth of merchandise, relieved herself with the bathroom door open and let her Yorkie puppy defecate on a Zac Posen gown.

Spears is reported to be hiring Jeff Kwatinetz, the talent manager recently fired by Kelly Clarkson.