Darren McGrady said the couple were happier than their on-screen versions and recalled a besotted dancefloor moment. The Netflix show’s fourth season focuses on the Diana-Charles-Camilla love triangle and the breakdown of their marriage.
The future king has faced backlash over the historical drama’s portrayal of events, which sees lonely Diana pining for her disinterested husband.
Charles and Camilla were even forced to turn off comments on their social media posts to avoid negativity.
But Mr McGrady spent many hours in the presence of Diana and Charles as he worked for The Queen at Buckingham Palace for 11 years.
Diana was also 16 when she first met the prince, then 29.
Some have defended the series’ portrayal of Charles, including former royal butler Paul Burrell, who agreed with the ‘cold’ and ‘uncaring’ depiction.
Princess Diana’s brother, Earl Charles Spencer, said last year the series caused him some concern because “Americans tell me they have watched ‘The Crown’ as if they have taken a history lesson”.
He said on ‘Love Your Weekend with Alan Titchmarsh’: “There is a lot of conjecture and a lot of invention, isn’t there? You can hang it in fact but the bits in between are not fact.”
A statue of Princess Diana is due to be installed in July this year to commemorate what would have been her 60th birthday.
It was commissioned by her sons Prince William and Prince Harry to “recognise her positive impact”.