A right Royal giggle: Cheeky William mocks bearded Harry only for cousin Peter Phillips to pull a 'bunny ears' prank on the Prince

•     Princess Anne's son had a cheeky grin as he played the trick on William

•     Peter, 36, shared a joke with William and Harry outside Royal service

•     Prince William appeared to be mocking his brother's new beard

•     Royals were attending annual service at church in Sandringham

By Lucy Crossley

Some of the younger members of the Royal Family appeared to be enjoying the Christmas festivities as they larked around outside the annual church service at Sandringham.

Among those having a right Royal laugh was prankster Peter Phillips who took advantage of Prince William chatting with younger brother Harry to play a 'bunny ears' trick on his cousin.

Princess Anne's son Peter, 36, had a cheeky grin across his face as he crouched down behind the Prince, ready to pounce.

Joking around: Peter Phillips tricks Prince William by making a 'bunny ears' gesture behind the Royal's head

Ready to pounce: Smiling Peter prepareds to play his prank on his cousin

Chuckles: Prince Harry grins as Peter Phillips pranks his older brother

The young royals were clearly enjoying their time together, with Prince Harry also appearing to be the butt of jokes over his new facial hair.

As he joked with Harry and Peter, William appeared to be mocking his brother's bushy beard by stroking his chin while the trio stood outside St Mary Magdalene Church.

Harry returned from his trek across the South Pole with charity Walking With The Wounded sporting the thick ginger facial hair and today told crowd's outside Sandringham he was planning on keeping it as it was a 'Royal tradition'.

Laughter: Stood alongside his younger brother, William looked to be stroking his chin, as if he was mimicking Prince Harry's bushy new beard

Humour: Prince William appeared to be mocking his brother's new facial hair as he joked with cousin Peter Phillips outside church

Challenge: Harry returned from his trek across the South Pole with charity Walking With The Wounded sporting the thick ginger facial hair

Christmas spirit: Cousin Peter Phillips shared a joke with the two Princes

Harry debuted his beard on his return from the Arctic, where he joined injured soldiers for a race to the South Pole, although the race element of the challenge had to be abandoned due to poor weather.

He still had the beard for a trip to Cape Town last week, and seemed determined to keep it when he arrived at church today.

However, some suggested that the beard had been trimmed for Harry's festive outing.

All smiles: William and Harry seemed in good spirits as they left the Christmas Day service