They were facing off against each other in the Best Pop Vocal Album category at the 57th annual Grammy Awards on Sunday night.

But Miley Cyrus and Katy Perry proved there was no rivalry between them by indulging in a friendly fondling session during the awards ceremony, held at the Staples Center in Los Angeles.

The pop princesses both went home empty handed and were commiserating by copping a cheeky feel of one another’s breasts.

Cheeky: Miley Cyrus happily groped Katy Perry’s breasts during the Grammy Awards at The Staples Center in Los Angeles on Sunday

Miley naturally initiated the antics by cupping Katy’s bosom while the purple-haired singer pouted for the cameras.

Katy then returned the favour for the Wrecking Ball hit-maker, but had clearly forgotten the lyrics to her breakout single I Kissed A Girl since she appeared mildly alarmed by the whole affair.

Miley later paid homage to her chart rival by sharing a snap of them holding hands, captioning it, ‘Dis iz kiewt @katyperry (sic)’.

Returning the favour: Katy looked less than impressed when it was her turn to cup Miley’s assets

The duo lost out to Sam Smith at the Grammys, who scooped the prize for his soulful album In The Lonely Hour, but still had a whale of a time at the bash.

Miley, 22, was far more demure than her usual standards, wearing a black Alexandre Vauthier gown.

The number might have looked tame from the front, but it screamed sex appeal when she turned around to reveal a plunging back and daring cut-outs along the sides.

Firm friends: The girls, who were competing for Best Pop Vocal Album,  have become well acquainted

Meanwhile, Katy, 30, was draped head-to-toe in jewels, wearing a beaded nude gown which sparkled under the spotlight.

She set off the glamorous number with a statement belt, dazzling drop earrings and simple Sophia Webster sandals.

Katy – who was also nominated in the Best Pop Duo category for her collaboration with Juicy J, Dark Horse – took to the stage to perform piano ballad By The Grace Of God from her third album Prism.

The Grammys will be on UK TV on Monday 9 February at 9pm on 4Music (Freeview 18, Sky 360 and Virgin 330).