In the build-up to the big day, US TV channel Lifetime has released a film documenting their love story.
But a particularly bizarre scene shows Harry – played by Murray Fraser – addressing Prince Charles and Camilla Parker Bowles – played by Steve Coulter and Deborah Ramsay.
In it, he claims that the pair “should have been able to be together from the start” – implying that the two should have got married before Charles, his dad, wed Princess Diana, his mum.
“you should have been able to be together from the start”
Prince Harry, in Harry and Meghan A Royal Romance
“I think sometimes, out of everything that’s been done to you two, how they told you who you could marry – you should have been able to be together from the start,” he says.
More bizarre still, Camilla replies: “But then you wouldn’t exist and the world would be a far less wonderful place.”
Then, clearly moved, Harry looks across at his partner Meghan before excusing himself and leaving the table.
The scene could refer to the relationship started by Charles and Camilla in the 1970s, long before Diana was around.
But their romance ended in 1973 and there have long been rumours that this was against their will – not least because the pair remained close.
The rest, of course, is history and Charles wed Diana in 1981 before fathering William and Harry in 1982 and 1984 respectively.
The couple split in the early 1990s before Diana’s tragic death in a Paris car crash in August 1997.
Charles and Camilla, meanwhile, got married in 2005 – over 30 years after they first met.
The clip is from the 2018 movie Harry and Meghan: A Royal Romance, which is yet to be aired in the UK but has already got fans talking.
The controversial film made headlines after the actors playing Harry and Meghan have a steamy romp.
Taking to Twitter, one fan said: “It’s actually really good, I want to watch it again.”
And a third even admitted: “I wish I was a royal after watching it.”
Harry & Meghan: A Royal Romance airs at 2:45pm 19th May on Channel 5.