In the audio tapes, Diana said she was not aware of the royal dress codes and just wanted to dress like other people her age.
She added: “I thought it was OK because girls my age wore this dress. I hadn’t appreciated that I was now seen as a royal lady.”
Later on, she told Mr Morton: “It was a horrendous occasion. I didn’t know whether to go out of the door first.
“I didn’t know whether your handbag should be left in your left hand or your right hand.
“I was terrified really – at the time everything was all over the place.”
The Princess wore it during a screening of a tell-all documentary about Charles, in which he admitted he had cheated on Diana with Camilla Parker Bowles.
Kerry Taylor, whose company auctioned off ten of the most recognizable Diana dresses in 2013, told womanmagazine.co.uk. said: “We called that ‘The Revenge Dress’ [because] she wore that the same evening Prince Charles confessed to his adultery with Camilla.
“While some would have been like, ‘I can’t face it this evening,’ Diana went out in that dress looking drop-dead gorgeous.
“She made a big statement right there.”