Paris Hilton jumped out of a cake at her boyfriend's birthday party.

The blonde socialite threw the surprise party for Doug Reinhardt at her Beverly Hills mansion last Saturday and wore a sexy hot pink outfit and a black diamond mask as she burst out of the giant-sized sweet treat.

Paris Hilton jumps out of cake
Paris Hilton jumped out of a cake at her boyfriend's birthday party.

The blonde socialite threw the surprise party for Doug Reinhardt at her Beverly Hills mansion last Saturday and wore a sexy hot pink outfit and a black diamond mask as she burst out of the giant-sized sweet treat.

Paris and Doug....partied with friends until 3am

A source told the New York Post newspaper:

"Paris went all out for her man's birthday. No expense was spared. He had no idea about the party and was so happy."

Paris was so keen to impress 'The Hills' star - who she reunited with in the summer when he whisked her away on a romantic break to Fiji - she organised for rap group Three 6 Mafia and hip-hop star Ya Boy to perform for partygoers.

Guests including Hollywood beauties Hayden Panettiere and Kristanna Loken, partied until 3am at the nightclub Paris has built in her home, while home videos of the couple were screened throughout the mansion.

Doug is not the only star to be presented with a giant cake on his birthday.

When Hollywood actress Katie Holmes turned 30 last December, her husband Tom Cruise surprised her with an enormous five-tiered sponge.