It’s no secret that “American Idol” judge Simon Cowell isn’t exactly best buddies with host Ryan Seacrest, but the caustic critic went a step further at Thursday’s "Mavericks" Details magazine party when he dissed the cover of the April issue featuring Seacrest.

“There looks like a lot of work has been done — Ryan doesn’t look that good in real life,” Cowell told Pop Tarts with a groan. “As for the report that he’s the 'King of Media' — I presume he wrote the article himself. It’s annoying.”

And since when has Randy Jackson been so quick to side with Simon and rag on Ryan?

Video: Pop Tarts Talk

“I think they built up the chin a little bit to make him look more like a footballer, like he’s really muscular and virile, but they didn’t quite make it,” Jackson added. “I don’t know what the world is coming to if they’re calling Ryan a maverick.”

Despite the snide statements, Seacrest didn’t stop smiling all night — and rightfully so.

“I’m sure Randy and Simon will be champing at the bit to talk about tonight and to talk about the fact that they at their age and with all that they’ve done didn’t make the list,” Ryan retorted. “But you know, there are other things that they can accomplish, like lifetime achievement awards and things like that, which is good for them.”

Indeed, it seems the 33-year-old media personality finds it fun to highlight the fact that his fellow reality stars are, well, a little older.

“I am surprised they even came tonight. I had to pick them up, I had to get them dressed, I had to get them dinner, I had to get them hydrated, so yes, I am surprised,” Ryan added. “I’m surprised they made the walk up the hill at their age.”

But once inside the swanky poolside soiree, Tarts spotted the threesome smiling and sipping Grey Goose cocktails like the best of buddies. Hmmm, is all that fighting in the name of ratings?

Big 3-0: Federline Parties With Pussycat Dolls and Attorney

Numerous “celebrities” celebrated the milestone 3-0 birthday over the weekend.

On Friday night, Kevin Federline and his (very large) entourage of family and friends hit up Sin City, where Britney’s ex got down and dirty on the VIP stage at PURE — alongside his attorney Mark Vincent Kaplan and his other ex, Shar Jackson.

Despite some speculation that Federline and Jackson may have rekindled their romance, an inside source told Pop Tarts that the apparent “lingering greeting” between the two (and the fact they headed off to an after-party at Noir Bar together) “meant nothing."

“Shar and Kevin are very supportive of each other — they have children together, so of course they have a special bond,” our source said. “But Shar being there meant nothing romantically — they are just friends.”

Despite telling the packed party-house that he had “no voice” and “lost all his money playing craps," we’re told Federline did get particularly excited when the Las Vegas Pussycat Dolls popped by to put their paws into a super-sized birthday cake and of course gave him a super-sexy rendition of “Happy Birthday.” …

But back in Beverly Hills on Saturday, Perez “Queen of Media” Hilton celebrated his big 3-0 with grand fiesta involving enchiladas, coconuts and, ah, odd entertainment.

The blogger was given the “gift” of a having a friend/magician stick numerous pencils, scissors and a drill up his nostrils. However, Perez seemed more excited (and somewhat more flattered) by the idea that he was referred to as “Paris” Hilton throughout the evening.

The other Pussycat Dolls (the all-girl pop group) also stopped by to share the love with a stripper-like sequence just for Perez. Amanda Bynes, Jerry O'Connell and Kim Kardashian were also on hand (either they're very brave or smart enough to win over the celeb-skewering blogger).

We also think Spencer Pratt pulled a smart move in getting his girl Heidi Montag out of the party relatively early after what may have been one too many margaritas. Tarts noticed Pratt helping up a little off-balanced Montag from the lounge before escorting her hastily toward the exit. …

Nicole Richie Obsessed with Herself?

Nicole Richie (finally) has a slightly fuller and more fabulous figure, and it seems the new mama is more than happy to give photogs much more than just a “flash” of her beautiful bod.

Donning a black babydoll dress, Richie stole the spotlight at the Prada Presents Trembled Blossom bash on Wednesday night, where she spent the evening outside on the carpet.

According to our sources, the former “Simple Life” starlet refused to talk to the press but was more than happy to pose for lots of pictures.

“It was hilarious — I’ve never seen anything like it,” our insider said. “This girl knows how to pose and she made sure she went up and down the line pulling her signature smile for well over half an hour.”

Nic eventually made her way into the swanky store’s soiree, but as the photo ops were over our spies spotted her en route to the exit before too long.

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