Princess Mary is known for being an understanding wife – happy to let her husband, Crown Prince Frederik, travel the world without her.

But we wonder how thrilled the princess, 37, will be to see photos of Frederik looking familiar with a Mary lookalike on a yacht with friends in Sydney.

Spending a lazy afternoon on the Magic V yacht docked at Woolloomooloo’s Finger Wharf, the prince, 41, lounged on the deck, his foot draped around the back of his brunette companion. She leaned back into his leg and appeared very relaxed.

Allan Pease, body language expert and author of Why Men Want Sex And Women Need Love, believes the woman looks very comfortable with Frederik.

‘This mystery woman feels she has the right to be sufficiently intimate with him by sitting on his leg,’ he explains.

Body language expert Dr Lillian Glass feels the prince is ‘trying to maintain his cool. He’s holding on to his hands, meaning he’s trying to contain himself.’

Allan Pease adds: ‘He seems to make a point of looking only at her eyes, which is a difficult task for any male in this position.’

The photos may reflect nothing more than friends enjoying a day on the harbour, but they hardly dispel a playboy prince’s reputation.