Ricky Gervais is "stressful" to work with.
The British funnyman's writing partner Stephen Marchant admits that every time they begin work on a new venture, he insists they will never collaborate again because it is just so taxing.
He explained: "I always find filming quite stressful, partly because of the time constraints and partly because of working with Ricky. Every time we finish a project I say I'm never working with you again, I openly say it to him.
"We just sit around and talk endlessly. We use a dictophone now to ad-lib the scene and act it into the dictophone. That way you're not constrained by thinking what's the beginning, middle and end because that is what is daunting. We put post-it notes on the wall like 'Brent does funny dance' and build ideas around it. In that case Ricky actually did that dance."
Marchant also explained how Gervais's infamous dance - performed by his "Office" character David Brent - was inspired by several pop bands.
He told Absolute Radio DJ Christian O'Connell: "Ricky was mucking around showing me how he imagined boy bands like Backstreet Boys to dance and I thought it was the funniest thing I had ever seen."