Former child star Miley Cyrus shocked guests at her boyfriend Liam Hemsworth's birthday party by posing suggestively with a cake shaped like a man's privates.

The singer/actress, 19, has gained a reputation as a wildchild since graduating from her days on kids' show Hannah Montana, attracting controversy for her skimpy stage outfits, raunchy dance routines, bong-smoking, and party-loving lifestyle.

Now, she has risked further criticism after a series of photos emerged online showing her simulating oral sex with Hemsworth's phallic chocolate cake at his 22nd birthday bash earlier this month.

In the images, posted on TMZ.com, Cyrus is shown pretending to lick and suck the sweet treat and cutting it with a knife during the party at Los Angeles nightclub Icon on Saturday.

She is also seen posing with a female pal while suggestively sucking her finger, dancing on a podium in a tight black dress and ripped stockings, and locking lips with Hemsworth on the dance floor.