Fergie and Quentin Tarantino celebrated their birthdays with a joint bash last night in Las Vegas.

“We wanted to do something that was crazy and a lot of fun,” she told Us Weekly.

The pair — who filmed a hot and heavy love scene in Tarantino's 2007 flick Grindhouse — spent the afternoon with friends at the Mirage Hotel’s Bare Pool Lounge.

Fergie (who turned 33) and Tarantino (who turned 45) caught the 7 p.m. performance of Cirque du Soleil's Beatle-themed show "LOVE." (They devoured cupcakes backstage, says a source.)

They then partied into the early morning hours at club Jet with Fergie's fiancé Josh Duhamel, Daryl Hannah, and rapper Nelly.

(Guest Kid Rock bought The Dutchess a hot dog toaster called the “Hot Diggity Dog.” “You put the bun on one side, and you put the hot dog in the little hot dog holes, and it pops out of the toaster in about a minute, and your hot dogs are ready to go,” Fergie told Us Weekly.)

Further putting those pregnancy rumors to rest, Fergie sipped on wine throughout the night.

At 2:30 a.m. at Jet, Fergie and Tarantino were presented with a birthday cake.

Tarantino "grabbed a handful" and threw it at Fergie, an eyewitness told Us Weekly. She then tossed a piece right back at him before "laughing and hugging him and heading back for the Mirage Villas, where they were staying," the onlooker adds.

As the group walked out the door, the DJ played Fergie's hit "London Bridge."