Miley Cyrus is showing no signs of growing up sensibly as she celebrated her 22nd birthday with a wild party at Factory Nightclub in Hollywood.

The singer and actress shared snaps on her Instagram account of herself riding a bucking bronco shaped like a giant penis, and licking a giant pizza-shaped birthday cake.

Miley was pictured partying with her rumoured new boyfriend Patrick Schwarzenegger, son of Terminator star Arnie, who she is thought to have begun dating in October and has been pictured smooching several times.

Miley Cyrus and Patrick Schwarzenegger
(Mark J Terrill/AP)

A video has also emerged online of Miley dancing topless at the party to MC Hammer’s Can’t Touch This, covering her nipples with her hands and poking her tongue out at the camera.

Miley wore a neon faux fur jacket over a neon mini dress with a cut out midriff. She accessorised with flowers in her hair and glittery hearts on her face, with a glow-in-the-dark dummy around her neck.