It seems the romance between Kate Hudson and comedian Dax Shepard is definitely off and things between the comic and "Heroes" star Kristen Bell are definitely on.

The comely new couple was caught getting cozy together at Bahamas hotspot Aura Nightclub at Atlantis last Thursday, where they danced and drank into the wee hours.

"At first they seemed a little awkward together and with the attention," our spy said. "But eventually they relaxed; I guess it is never easy 'coming out' with a new relationship."

And even though former "Laguna Beach" star Kristin Cavallari has boogied the night away many times in Hollywood, it was a first for her in Sin City as she finally turned 21 on Friday.

Sporting a new 'do of lush long locks, Cavallari had to wait outside party palace PURE until midnight, when the clock ticked into her birthday. At that point, she began a two-day bender ... and according to our spy, Kristin spent the night slamming shots and dancing with Arizona Cardinals quarterback Matt Leinart.

"They had a lot of fun together," a Cav pal told Tarts. "But they left separately. Kristin is totally in love with her boyfriend [actor Nick Zano]."

But the birthday babe was back in the limelight the next night at LAX, where she shared cake with the crowd and apparently enjoyed (lots of) Red Bull and Belvedere vodka.

Perhaps Kristin has a thing for men with muscle — this time, she hard-partied with Buffalo Bills center Melvin Fowler and NBA superstar Gary Payton until the lights came on.

Meanwhile, another (almost) landmark birthday was being boozed away down the road at the brand spankin' new club at The Bellagio, The Bank. John Legend seemed more than pumped to turn the big 2-9, but the notorious ladies' man wasn't exactly on his best behavior.

And while his new leading lady, 22-year-old Norwegian model Christine Teigen, made sure she practically glued herself to his hip all night, Legend reportedly could not help looking.

"Old habits die hard," our inside source said. "Whenever he had the chance, he was coyly checking out the eye-candy … especially the hot waitresses who held nothing back."

Beyonce Suffers Wardrobe Malfunction?

Oops! Britney, Paris and Lindsay all did it — but Beyonce?

The singer seems to have gone from "Dreamgirl" to showgirl as some recent on-stage snaps show Knowles' nether regions as she performs on a pole (speculation is now stirring that the pics are Photoshop fakes.)

And while her longtime lover Jay-Z hasn't spoken out about the apparent slip-up, buddy 50 Cent had something to say.

"I don't think she meant to do that; Beyonce doesn't need to do that," the rapper recently told New York's "Real Talk" radio.

Perhaps "B" was having a problem with punctuality and was just so pumped to perform that she accidentally put on plus-size panties … after all, Pop Tarts spotted Miss Knowles making a mad dash through The Mirage in Sin City last Sunday night to make it across the Strip to sing at her scheduled time.

And although this group of fans wasn't exposed to quite so much of Beyonce's "personal" life, the Grammy-winner definitely didn't disappoint.

"She looked so amazing and the show was unreal," a concertgoer told Tarts. "And even if she wasn't wearing the right underwear, everybody was just so into the music I doubt anyone would have cared."

Meanwhile, rumors are still running rampant that Beyonce married Jay-Z in Paris on a recent promotional trip. While we didn't spot any extra bling on their fingers last week, word on the street is that an announcement may come soon … stay tuned.

Britney Busted With Pap Pal in Palm Springs

Were we dreaming, or didn't Britney Spears have a breakdown late last week, lose visitation rights to see her kids, have a hissy fit over Dr. Phil's visit and spend some time in Cedars-Sinai Medical Center?

Well, all that seems to have been totally forgotten, because the Britster was back to her bizarre business on Sunday.

Pop Tarts has been told that the "Crazy" crooner was again hanging around with paparazzo Adnan Ghalib, but instead of hoppin' in Hollywood, these two were getting greasy at the Daily Grill in Palm Desert near Palm Springs. Brit was also boozing over breakfast with a mimosa, according to reports.

And just before you start to think that Britney's trip out of Tinseltown and up the California coastline could be the start of the recovery road, think again. The star-studded Palm Springs International Film Festival is currently taking place nearby, which means plenty of photo ops for the fallen star.

Hmm — raise your hand if your sympathy for Spears is less than overflowing.

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