Her onstage antics during her north American tour have included swigging beer, throwing back shots and writhing with female audience members - not to mention singing and dancing.

So after all that, it is understandable that Rihanna would be feeling a little sleepy.

The singer looked like she may have forgotten to change out of her nightshirt as she left her New York hotel yesterday.

Sleepy? Rihanna was pictured out in New York yesterday wearing what looked like a nightshirt

She beat the 32 Celcius (90F) New York heat by going without trousers, adding only large hoop earrings and tan brogues to the ensemble as she shopped with her entourage including best friend Melissa.

The 23-year-old seemed to have bed on the brain, posting a picture earlier of her customised 'RiRi' pillowcases provided by her hotel.

Rihanna tweeteed: 'My hotel has "RiRi" stitched into my pillowcases, how f****** Raaaddd is that??! #rockstars*** #wheretheydodatat #IheartNYC.'

At her sell-out concert in Atlantic City' Borgata Hotel & Casino & Spa the night before, Rihanna indulged in even more risque behaviour than usual in front of an audience full of young fans, including slugging alcohol, making offensive hand gestures and overtly sexual dance moves.

Bed on the brain: Rihanna tweeted a picture of her customised pillow cases in her New York hotel

The star wore an array of typically risqué outfits, including ultra short shorts and colourful cropped top and a slinky silver sequinned dress for the performance.

And in another typically outrageous dance move, she took part in a girl on girl dance with a female member of her dance troupe.

The singer is often seen indulging in some risqué dances - she once famously performed a lap dance with a female fan on stage, and gyrating on top of her.

But her risqué moves, which often extend to her music videos, have gained Rihanna some unwanted publicity.

Earlier this year, she was forced to defend her controversial new music video Man Down, insisting 'this is the real world'.

Drinking it down: Rihanna swigged from a bottle of Corona on stage in Atlantic City, New Jersey last night

Boozing and swearing: Rihanna drinks down a shot from a glass and flips the finger on stage

Boozing and swearing: Rihanna drinks down a shot and flips the finger during the gig wearing a typically scantily clad outfit of ultra short shorts and a silver sequinned mini dress

Taking to Twitter, she attacked her critics, claiming she was a 'rockstar not a parent' and saying she had 'the freedom to make art'.

Man Down attracted the wrath of the Parents Television Council, who blasted Rihanna for showing a 'cold, calculated execution of murder.'

But Rihanna, herself a victim of domestic violence, disagreed with the criticism.

'I'm a 23 year old rockstar with NO KIDS! What's up with everybody wanting me to be a parent? I'm just a girl, I can only be your/our voice!' she wrote.

Risqué: Rihanna is developing a reputation for some overtly sexualised dance moves, like last night's girl-on-girl number

And in an apparent direct response to the PTC she added: 'The music industry isn't exactly Parents R Us! We have the freedom to make art, LET US! Its your job to make sure they don't turn out like US.'

The council said in a statement: 'Rihanna's personal story and status as a celebrity superstar provided a golden opportunity for the singer to send an important message to female victims of rape and domestic violence.

'Instead of telling victims they should seek help, Rihanna released a music video that gives retaliation in the form of premeditated murder the imprimatur of acceptability.'

'A defiant Rihanna praised her fans for their support, tweeting: 'Thank you for the amazing response on ManDownVideo. I love you guys, and I love that u GOT IT!!'

Two fingered salute: Rihanna has appeared during her tour in an array of barely there outfits including this matching outfit of multi coloured bra top, marching shorts and fishnet tights, seen here in Florida on Friday

It was the second time in as many weeks Rihanna attracted criticism from the PTC - she was also slammed for her kinky performance with Britney Spears at the Billboard Awards.

Last year, Rihanna was also criticised for being too provocative when she performed her hit song What's My Name, for the X Factor finale in the UK.

Once again she thrusted her way through her solo performance in tiny pants and strapless bra.

The X Factor had 3,215 complaints lodged with the regulator making it the most moaned-about show last year. with no other programme coming close to talent show.

This morning, after last night's provocative performance, the singer looked a little more conservative as she stepped out in New York wearing a shirt dress.