When Boujis nightclub is in the news it’s usually because Princes William or Harry have been pictured stumbling out of it looking somewhat the worse for wear.

So it was refreshing to see one young Royal making a perfectly dignified exit – and giving her elder cousins a lesson in immaculate behaviour at the same time.

Princess Beatrice was spotted outside the fashionable South Kensington venue early yesterday with her boyfriend Dave Clark.

Despite it being the small hours of the morning, the 19-year-old was clearly intent on maintaining her composure. She smiled happily for photographers as she made her way demurely into a taxi with her 25-year-old beau.

And it was all done without the Princess spilling out of her purple strapless dress or dropping the oversized blue beanie hat – the latest teenage fashion item – which she was clutching.

Beatrice and her boyfriend were introduced by Prince William and have been dating for a year.

The two have a circle of wealthy friends who include Sir Richard Branson’s son Sam, Sean Brosnan – son of former James Bond star Pierce Brosnan – and William’s girlfriend Kate Middleton.

Dave Clark is the son of Michael Clark, a wealthy American who was a senior lawyer at Cadbury Schweppes until he retired last year. His family live in a £5million mansion in Hampstead.

Beatrice is said to be smitten by her boyfriend, who works for Sir Richard’s Virgin Galactic space tourism project, and she has apparently told friends he is ‘the one’.