Plenty of famous faces joined the Friends cast for special episodes of the 90s sitcom throughout it's ten seasons.
Celebrities including Jennifer Coolidge, Sean Penn, Winona Ryder, Brad Pitt and Bruce Willis have all had cameos on the legendary show, and as far as we're concerned, they all had a ball in the process too.
However, that isn't the case for all of the people who were lucky enough to bag a gig as a guest star on Friends.
Take The One with Ross's Wedding, for example - Friends fever was well and truly gripping the UK in 1998, so stars who were hoping to get in on the action which unfolded in the two-part season finale were forming an orderly queue.
Advert
Ross Geller was set to get hitched to his blushing bride Emily Waltham in London and the rest of the gang were just dragged along for the ride.
Friends fanatics may remember that the Duchess of York, Sarah Ferguson, made an appearance in the episodes, as well as Virgin tycoon Richard Branson and Stuart Little star, Hugh Laurie.
As well as this interesting trio, Olivia Williams offered up her acting talents to the sitcom and starred as the flirty bridesmaid and friend of Emily's, Felicity, who comes on to Joey Tribbiani.
Although it sounds like a right laugh, the actress said it was 'harrowing' rather than a hoot.
The Sixth Sense star, 55, revealed that she realised things didn't run quite as smoothly behind-the scenes as they appear to do on TV.
Advert
Speaking to The Independent, Olivia recalled how she was left particularly uncomfortable by the treatment of a fellow actress who was also guest starring on Friends at the same time as her.
She explained: "Well, just as an example, I was taken to the studio in a shared car with a wonderful actress whose character, I think, was called ‘Old Woman’."
Describing the unknown celeb as 'distinguished' and 'very good', the Brit then went on: "At one point, a producer – who shall remain nameless – just yelled at her: ‘You’re not funny!’
"And she didn’t come back the next day. So, that was alarming."
Olivia - who portrayed Camilla Parker Bowles in Netflix's The Crown - then opened up about the beauty standards she felt were forced upon female actresses on set.
Advert
The actress continued: "Oh and Friends was a brand, and you had to fit the brand. You go into hair and make-up and you’re told, ‘There’s a look here, this is what we do.’
"And that involved, essentially, plucking off all of your eyebrows."
The 55-year-old said she had to beg the crew not to completely butcher her brows, telling them: "Literally, ‘please don’t take my eyebrows off, I might need them in another job!'"
"But yes, that’s the sense in which it was harrowing," Olivia concluded.
Advert
Harrowing indeed.
Featured Image Credit: DANIEL LEAL/AFP/Getty Images/NBCTopics: Celebrity, Friends, TV, London, UK News, TV and Film