Diana's heartbreaking engagement announcement

Prince Charles famously replied, "Whatever 'in love' means" when an interview asked him how he and Lady Diana were feeling, at their engagement announcement.

Now, body-language expert Robin Kermode has decoded the entire interview – and the results are heartbreaking.

“It is particularly poignant to revisit the famous engagement interview after 36 years. We shouldn’t forget the scale of the media pressure on these two young people – a pressure that most of us couldn’t possibly handle," Robin told the Daily Express.

“If we look at these clips from a body language perspective, we must be aware of the historic lens we watch it through. The manner and style of the interviewer’s questions, and of their responses, seem almost from another world.”

“As our facial muscles are busier when we’re speaking, we can put on a ‘mask’ or a ‘front’ quite easily, but having to listen to comments about ourselves when we are trying to be still will reveal lots of little signals."

Throughout the interview, both Charles and Diana wear serious expressions, and it isn't simply because they're undergoing a major life change.

“Some of the clips appear to show a contrast between Charles and Diana," Robin points out.

"Charles looks assured while Diana often looks sadder when she is listening – her lips and mouth are held together, here eyebrows lifted and her cheeks pushed forward with watery eyes.”

And Robin believes Charles referring to their romance as "business" is especially telling.

"I think one of the most interesting phrases from Charles was the use of the word ‘business’ when asked about their courtship," he explains.

"He then spends several moments looking down avoiding the camera. His lip corner pull inwards and then his mouth is pulled tight and upwards suggesting sadness."

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