Last week her husband was the hit of an LA premiere, pictured being fawned over by the likes of Cindy Crawford and Sharon Stone but now it is his wife Katy Perry's turn to raise a few eyebrows, after being spotted larking about with one of her male backing dancers in the wee hours in Rio.

The singing superstar was pictured sticking out her behind suggestively as her friend got up close and personal.

Perry, 26, was letting her hair down at an after-party for the Rock in Rio music festival in Rio de Janeiro, which she performed at in front of a 10,000-strong crowd.

She took to the stage for her extravagant headlining set following a stunning fireworks display.

Katy tweeted earlier: 'I'M READY TO ROCK RIO! 100,000 people tonight! I LOVE YOU BRAZIL... You've waited so long for me so tonight I'm gonna give it to you!!!'

The Teenage Dream singer remained at the festival after her own set to watch her good friend Rihanna perform at 2.30am.

She arrived at the after party with her entourage around 3.30 and stayed on until ten in the morning.

The singer was pictured dancing and sipping drinks with other revelers. Rihanna arrived at the party at 7am but left an hour later, according to onlookers.