Well one never! The Crown’s Helena Bonham Carter bumps into Emma Corrin 

As Princess Diana and Princess Margaret in The Crown, they have a frosty on-screen relationship.

But Emma Corrin and Helena Bonham Carter seemed thrilled to bump into each other in a chilly London street last week.

Ms Corrin, 25, and her mystery man had just finished looking at wedding dresses in a store window when they spotted Ms Bonham Carter and her young lover Rye Dag Holmboe on Boxing Day.

The quartet, who were out walking their respective dogs, chatted animatedly, while observing social-distancing rules.

Their encounter came after Ms Corrin, wheeling a bicycle and wearing flared jeans and a black leather coat, had been admiring gowns made by Scottish designer Joyce Young.

The designs, which start at about £1,500, are sleeker than the gown worn by Ms Corrin to recreate Diana’s ivory taffeta dress with a 25ft train.

In November, Tatler magazine named Ms Corrin as one of the 100 most eligible women in Britain, but she has been seen with her bespectacled friend several times over recent months, even though his identity remains a secret to the wider world. 

Ms Bonham Carter, 54, who wore a black puffer jacket, initially kept her relationship with Mr Holmboe, 32, a secret until The Mail on Sunday revealed they were dating in October 2018.

Last year, the actress described the Norwegian writer as ‘magic’, adding: ‘We met at a wedding. A totally random thing since both of us nearly didn’t go. It was one of those moments that was so chance and ended up determining so much. A really happy accident, and it’s an amazing thing.’

The actress’s uncle, Mark Bonham Carter, once dated Princess Margaret, who is shown in the latest series of the Netflix drama as feeling increasingly marginalised as the public’s attention moves towards Prince Charles and Diana. 

In one scene, Diana is seen unwittingly upstaging Margaret by interrupting an uproarious anecdote.

Royal experts question the accuracy of The Crown, but Netflix has refused calls to run disclaimers before episodes admitting that many storylines are fiction.