Princess Beatrice and Dave Clark enjoy a night out with James Middleton"s girlfriend Donna Air

Princess Beatrice and her boyfriend Dave Clark enjoyed a night out with James Middleton“s girlfriend, Donna Air. Having attended the Butterfly Ball in Battersea Evolution, the trio headed to LouLou”s nightclub to let their hair down.

Beatrice kept her look simple with a black dress, jacket and shoes, adding a touch of sparkle with a gold clutch bag. She strolled hand-in-hand with her boyfriend of more than six years, Dave, previously frequented by James” sister Kate Middleton and Prince William.

Donna also chose an all-black ensemble. Her black dress was detailed with sheer sleeves and neck as well as a low bag. Taking a leaf out of Beatrice“s style book Donna also carried a striking gold clutch bag.

Private members club LouLous is also the same venue where James and Donna were first debuted their romance. In April businessman James, 27, was photographed hand-in-hand with TV personality Donna, 33, who looked coy as the cameras captured their moment together.

James did not join his new girlfriend but Donna“s night out with his brother-in-law”s cousin is a sign of their blossoming friendship.

Princess Beatrice and her sister Princess Eugenie enjoy a good relationship with James and the trio recently stepped out at an exclusive Mayfair restaurant to toast socialite Heather Kerzner”s 44th birthday.

The gathering, which was held at Downtown Mayfair, was a sure indicator that the Middleton family members have been warmly welcomed into the royal fold as Donna seems to be as well.

Earlier in the evening Donna attended The Butterfly Ball: A Sensory Experience with Beatrice“s mother, Sarah Ferguson. The event, in aid of the Caudwell Children”s charity, also drew famous faces including, Tamara Ecclestone, Joan Collins and designer Kelly Hoppen.

“Lovely night at the Butterfly ball 4 Caudwell Children”s Trust,” tweeted Joan Collins with a snapshot of herself with Sarah Ferguson. “With @SarahTheDuchess, @johndcaudwell and @cla1re24!”

“Really excited to come!” said Sarah, Duchess of York before she headed to the glamorous ball. “What a great Charity xx.”