Los Angeles- Marion Cotillard was shaking and singing, Javier Bardem gushed about his hot date and Daniel Day-Lewis was thirsty for a milkshake. It all happened backstage at the Oscars.

The notoriously serious Day-Lewis celebrated by puckering up — kissing fellow winner Bardem on both cheeks — before explaining why he’d smooched George Clooney on his way to collect his best actor Oscar at the Kodak Theatre.

“I had to kiss someone,” Day-Lewis said. “I kissed my wife, and in the interest of parody, I kissed George.”

Speaking of parody, Day-Lewis addressed his now-classic line from “There Will Be Blood,” saying he’s more than happy to drink your milkshake. “I’m very much looking forward to all milkshakes I can drink for the next 25 years or so.”

Day-Lewis was less sunny when asked what a serious actor like himself does for laughs. “I’m not telling you,” he said with a sly grin. “It’s none of your f– business.”

Clutching her shiny new best actress statuette, surprise winner Marion Cotillard was quivering and short of breath when she arrived backstage in a flurry of applause.

“I’m totally overwhelmed with joy and then sparkles and fireworks and everything which goes like bam, bam, bam!”

Obliging a request from the Oscar press corps, the “La Vie en Rose” star reluctantly sang a few lines from the Edith Piaf tune “Padam, Padam.”

With his “No Country for Old Men” bob haircut long gone, Bardem beamed backstage. Though rumored to be dating fellow gorgeous Spaniard Penelope Cruz, the no-surprise supporting actor winner was looking forward to spending the night with his official date — his mother, Pilar. “It’s a great companion, to have her on my side, and she always calms me down,” Bardem said.

“Michael Clayton” star Tilda Swinton was still processing her supporting actress triumph when she met the press, joking that she had a “reverse ‘Zoolander’ moment” when Alan Arkin announced her name.

“I’m still recovering from that moment, and I have absolutely no idea what happened after that,” Swinton said. “You can tell me my dress fell off and I’d believe you.”

Fire-haired Swinton kept her cool when a reporter mentioned her “unconventional love life” — more specifically, reports that she has both a husband and a boyfriend.

“I don’t have a husband,” Swinton said. “I’ve never been married.”

The actress said she’s raising her 10-year-old twin sons with their father, 67-year-old John Byrne, while in a relationship with 29-year-old German artist Sandro Kopp.

“I have children with someone else, with whom I’m bringing up my children,” Swinton said. “And I’ve lived with someone else, my sweetheart, for the last three years, and maybe it’s extraordinary that we’re really all friends.”

“Once” musicians — and best original song winners — Glen Hansard and Marketa Irglova are more than friends, but the couple shied away from PDA backstage.

Instead, Ireland native Hansard bragged about getting a congratulatory text message from Bono.

“Getting a text from Bono is the biggest thing that can happen to an Irishman,” he said.

“Juno” screenwriter and first-time Oscar winner Diablo Cody cleared up Stiletto-gate 2008, insisting she never agreed to wear shoe designer Stuart Weitzman’s million-dollar heels on the red carpet, despite an announcement from Weitzman last week.

“It was the silliest thing,” Cody said, lifting her leopard-print dress to reveal simple gold ballet flats. “These are regular shoes. … If I had a million dollars, I would help people.”

LOS ANGELES — Complete list of winners at the 80th annual Academy Awards, presented Sunday night at the Kodak Theatre in Los Angeles:

Best Motion Picture: “No Country for Old Men.”

Lead Actor: Daniel Day-Lewis, “There Will Be Blood.”

Lead Actress: Marion Cotillard, “La Vie en Rose.”

Supporting Actor: Javier Bardem, “No Country for Old Men.”

Supporting Actress: Tilda Swinton, “Michael Clayton.”

Director: Joel Coen and Ethan Coen, “No Country for Old Men.”

Foreign Language Film: “The Counterfeiters,” Austria.

Adapted Screenplay: Joel Coen and Ethan Coen, “No Country for Old Men.”

Original Screenplay: Diablo Cody, “Juno.”

Animated Feature Film: “Ratatouille.”

Art Direction: “Sweeney Todd the Demon Barber of Fleet Street.”

Cinematography: “There Will Be Blood.”

Sound Mixing: “The Bourne Ultimatum.”

Academy Awards Preparation Sound Editing: “The Bourne Ultimatum.”

Original Score: “Atonement,” Dario Marianelli.

Original Song: “Falling Slowly” from “Once,” Glen Hansard and Marketa Irglova.

Costume: “Elizabeth: The Golden Age.”

Documentary Feature: “Taxi to the Dark Side.”

Documentary Short Subject: “Freeheld.”

Film Editing: “The Bourne Ultimatum.”

Makeup: “La Vie en Rose.”

Animated Short Film: “Peter & the Wolf.”

Live Action Short Film: “Le Mozart des Pickpockets (`The Mozart of Pickpockets’).”

Visual Effects: “The Golden Compass.”