Sean "Diddy" Combs Photo by: Carmen Valdes / Retna
Diddy Party's Dress Code | Sean P. Diddy Combs
Agonizing over what to wear to P. Diddy's July 4 soiree at the PlayStation 2 party house in Bridgehampton, N.Y.? Don't even think about looking patriotic. "Even though he's calling it a Red, White and Blue party, you still have to wear all white to get in," rep Matt Heien tells us. "You can't even have a green alligator on your white shirt." Got that?

The revelry actually begins Friday night when Paris Hilton celebrates the launch of her new record label, Heiress, at the nine-bedroom, 13,000-sq.-ft. house, which sits on 6 acres and boasts its own pond. Jay-Z takes over the house on Saturday night to celebrate the launch of his new tennis shoe with Reebok, and then P. Diddy becomes the host on Sunday. Celebrities expected for the weekend festivities include Nicole Richie, Jason Biggs and Wilmer Valderrama.

Beyonce Watch
Speaking of Jay-Z, it was he and Beyonce dancing behind a wall of security guards at New York hotspot Marquee last Thursday, in case you were wondering ... Also looking out for the "Crazy in Love" duo was Beyonce's dad and manager, Mathew Knowles, who came out Monday night to the ASCAP Rhythm & Soul Awards at the Beverly Hilton, where Jay-Z was honored along with Rick James.

Playing Dad
On the new FOX sitcom Quintuplets, Andy Richter plays dad to five teenage kids – but offscreen he finds his 3-year-old son, Willy, keeps him busy and entertained. "The other day, Willy sang a couple of songs, while accompanying himself on the toy accordion, called, 'Mary Saw a Volcano, and She Ran Away' and 'They Gave Us Nuts, and We Cried and Cried and Cried,'" says Richter, 37, whose wife is Strangers with Candy's Sarah Thyre. "The songs are largely a repeating of the refrain. And he's allergic to walnuts, so he's writing what he knows."

Caught in the Act
Spotted recently:
Ja Rule, with 30 friends, at Marquee on Friday – but the club only allowed 10 to enter with him. Also there the same night: Bijou Phillips, Stephen Dorff and Nicole Richie.

Amber Valetta and actor Donovan Leitch with model-wife Kirsty Hume (and baby in tow), at L.A. nightspot Spider Club on Friday, hosting the Fashion 4 Change event. The evening, which included a fashion show by Clothing of the American Mind, raised funds for John Kerry's campaign.

Also spotted at the club Friday night: Paris and Nicky Hilton (who flitted back and forth between the Spider Club and Avalon Hollywood, in the same building), with their parents, celebrating their uncle's birthday. They were seated next to Wilmer Valderrama and Lindsay Lohan. Matthew Perry showed up with a bevy of women and one other guy. British soccer star Vinnie Jones was also there, with his best mate, actor Jason Statham (The Italian Job), and a gaggle of women. And Nick Lachey, sans his touring wife, Jessica Simpson, watched the dance floor from the sidelines with brother Drew and friends.

• Supermodel Maggie Rizer, hosting the Viva Glam Casino party commemorating the 20th anniversary of Design Industries Foundation Fighting AIDS at New York's Copacabana. Also at the event, which raised $300,000 for hundreds of AIDS organizations worldwide, were Moby, Chloe Sevigny, Lauren Bush and Queer Eye's Thom Filicia and Kyan Douglas.

• By KC BAKER, MARISA LAUDADIO, REBECCA PALEY, ANNEMARIE CRUZ and DOUG BRUNSWICK