David Attenborough and Queen Elizabeth II are not exactly well known for their sense of humour, but perhaps it's time to rethink that assumption...
Apparently, Britain's head of state is capable of being quite funny, as proven by footage from Liz and Sir Dave appearing together in an environmental documentary called The Queen's Green Planet.
The show is intended to celebrate a Commonwealth environmental project called The Queen's Commonwealth Canopy, which is aimed at planting more trees and creating forests around the world.
Because her name is on it and she is literally the Head of the Commonwealth, Lizzie has been drafted in to talk it over with Attenborough.
They seem to hit it off too, sharing a joke about a sundial that has been cunningly placed directly in the shade, out of direct sunlight. They literally throw shade at a sundial.
The jokes continue as they stroll through the gardens of Buckingham Palace, when their serene walk is spoiled by the sounds of a large aeroplane flying overhead.
The Queen remarks: "Sounds like President Trump, or President Obama".
OK, it's not exactly comedy gold, but it certainly tickled Attenborough.
The show - which will hit British screens next Monday - highlights the initiative to plant loads of new forests around the world. As well as documentary film royalty and actual royalty, Angelina Jolie also makes an appearance to big up the Queen's commitment to environmental change.
Jolie - who described the Queen as 'a really lovely lady who really cares about people around the world, and she really cares about the future, and she wants your grandkids and her grandkids to be able to be running around, enjoying nature and other cultures" - is filmed on a journey with her children to Namibia.
Once they get there they plant a tree in Queen Elizabeth's honour. She says: "The Queen's Canopy project means so much and will mean so much to so many people.
"You know when you sit up at night in a tent with your kids and they say, 'Why does the Queen of England care about planting trees in Africa?' And to be able to explain that to them is a really nice way of being able to explain kind of the world at large and what should matter and why."
The Queen and David Attenborough are both 91, but they are obviously both passionate about creating a better world for everyone to live in once they are gone.
Of the project, Britain's longest serving monarch said: "I mean they're all kinds of different trees, different places that they're growing in and all sorts of different types of forest.
"So, if all countries continue to plant, it might change the climate again."
We can only hope, Lizzie.
Featured Image Credit: PA