An overly-friendly Miley Cyrus cupped Katy Perry’s breast backstage before the latter got her own back at last night’s 57th annual Grammy Awards.

Cyrus wore a black Alexandre Vauthier gown with cut-out details as she posed and snuggled up to Perry, who shimmered in a beaded Zuhair Murad dress, behind the scenes at the star-studded ceremony.

The ‘Roar’ singer threw the cameras a sultry look as Cyrus placed her hand under her right boob, before doing the same to Cyrus and pulling a confused face as though her friend’s modest bust was just too small to even cup.

Cyrus didn’t seem to mind though as she continued to beam at photographers.

Perry made a powerful appearance at the Grammys yesterday as she took to the stage and performed ‘By the Grace of God’ with domestic abuse survivor Brooke Axtell in a statement of empowerment.

It marked the first major public appearance from the star since she headlined the Super Bowl half-time show last weekend.

See the stars arrive at the 57th annual Grammy Awards below: