Dance like nobody's watching, Beatrice! Party princess is lost in music with Sam Branson at star-studded WE Day concert 

She's been dubbed the party princess for her love of socialising and, not to mention her fondness for holidays.

But tonight Beatrice revealed why she's top of any A-list hostess's invite list - she can bust out a move with the best of them and make her friends laugh in the process.

The 27-year-old royal had friend Sam Branson in fits of laughter as she pretended to take her dance moves very seriously as they attended the WE Day concert at Wembley Arena.

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Princess Beatrice closes her eyes with concentration as she rocks out at the the WE Day concert but luckily her friend Sam Branson finds the funny side and laughs with her as she swings her arms

Sam Branson and Beatrice look serious as they dance in sequence along with audience members behind them

Beatrice shoots Sam an intense look as they put their arms outstretched, with their fingers pointing

The pair pulled a series of moves that wouldn't have been out of place in a Seventies disco but it soon became apparent that they weren't alone.

Around them, other concert-goers were making the same shapes, from flinging their arms in front of them and pointing their fingers to crossing their forearms across their chests.

While Beatrice stuck to her preppy outfit of a top over a smart white shirt, paired with a black skirt and button-up boots, Sam stayed wrapped up in a grey beanie and black biker jacket.

The pair were part of the VIP posse at the event that saw stars including Rita Ora address audiences.

Today's WE Day performance was planned to bring together world-renowned speakers, A-list performers and thousands of young people.

The event is held every year raise money for youth projects around the world to help young people take social action and is backed by Free the Children UK.

Sam either lost track of where he was in the dance or perhaps it was just a matter of losing interest

You put your two hands down... Beatrice looks focused as she thrusts her arms downwards

Everyone around Sam and Beatrice seems to be doing the same moves, lifting both arms at the same time

The pair smile broadly as they point to the side but Beatrice's friend to her right seems to be a beat behind

Beatrice sported a glamorous look last night when she attended the WE Day dinner hosted by Richard Branson, and she was once again joined by the billionaire's daughter Holly, 34, as she arrived at London stadium this morning.

The eldest daughter of Prince Andrew and Sarah Ferguson wore her hair in loose waves and kept her make-up to a minimum as she arrived at the concert to see Rita Ora and X Factor's Fleur East perform.

Close friend Holly, who is patron of the charity Free The Children, which runs the event, and co-chair of WE Day UK, kept it casual in skinny black jeans and boots, paired with a white jumper worn over a baggy blue shirt.

Beatrice stepped out in a preppy black blazer worn over a white shirt with button-up boots at the Wembley Stadium concert for We Day, which brings together speakers, performers and thousands of young people

Beatrice, 27, and friend Holly Branson, 34, had been out celebrating the night before at a lavish dinner hosted by Holly's father Richard at the Bulgari Hotel in London ahead of today's Wembley Stadium event

The girls posed photographs alongside Holly's sister-in-law Isabella Calthorpe, who kept cosy in a green, fur-lined parka, while Beatrice was seen greeting fellow guest, Canadian author Craig Kielburger.

Isabella, shares a series of connections to the royal family. She married to their great friend, Richard Branson's son, Sam, and has a one-year old daughter Eva-Deia with him.

She is also half-sister to Cressida Bonas, Prince Harry's ex and her other half-sister Gabriella Calthorpe, who acts under the name Gabriella Wilde is about to make her name on the small screen in Poldark. 

She certainly completed the high society trio with Beatrice and mother-of-two Holly.

Princess Beatrice and Holly are joined by Isabella Calthorpe, who kept cosy in a green fur-lined parka. While her friends were more dressed down, Beatrice went for a more preppy look and wore her hair in loose waves

Beatrice air-kisses Canadian author Craig Kielburger, who also attended last year's We Day event

Princess Beatrice played it safe in all-black ensemble at a dinner event at the Bulgari hotel, in London

The community-based project is part of of WE Schools, which gives educational resources to school groups, and children were able to volunteer to earn a ticket to the star-studded concert. 

When she stepped out last night for dinner, Princess Beatrice played it safe in all-black ensemble at the Bulgari hotel, in London.

She wore an inky dress paired with a blazer and court shoes to attend the WE Day UK dinner at the Knightsbridge hotel and showed her support for today's event.

Beatrice softened her black outfit with a puff-sleeve blazer and added some sparkle to her flared dress with a metallic clutch and patent heels, right, pictured with Holly Branson

The Princess wore her hair in bouncy curls and played down her make-up with a natural look.

The royal softened her dark ensemble with a puff-sleeve blazer and added some sparkle with a metallic clutch and patent heels.

Beatrice, who is rumoured to have landed a job with a New York-based fashion investment company, was snapped with Holly, who wore a forest-green asymmetric dress with zip detailing.

She paired her statement top with matching leather skinny trousers and  - in contrast to Beatrice - chose comfort with a pair of flat shoes.

American actress Marlee Matlin attended the celebration and smiled for the camera with Beatrice and Holly

Beatrice was supporting the celebration for WE Day, which kicks off tomorrow night at Wembley Stadium, pictured with Hanan Ahmed

American actress Marlee Matlin attended the celebration and smiled for the camera with Beatrice and Holly.

The Oscar-winning deaf actress also chose black in a knitted dress with cut-out detailing, but contrasted her outfit with her curled blonde hair.

Beatrice's new opportunity came after she completed a finance course at university in San Francisco but was back in London to attend the launch.

Her long-term boyfriend Dave Clark works for Sir Richard's spaceflight company Virgin Galactic. 

Beatrice and Holly are close friends and even scaled Mont Blanc together in 2012.