When Saffron Barker was announced as a Strictly Come Dancing contestant in 2019, many of the show's fans were left wondering who she was.
The two showbiz veterans are arguably the biggest names in the celebrity version of the social media reality show, airing in support of fundraising campaign Stand Up To Cancer, but that meant nothing to Barker.
As the players introduced themselves via their social media profiles, she admitted: "I feel rude because I don't know who Denise or Duncan is but they probably don't have a clue who I am either!"
The 20-year-old also dropped another clanger when she noticed that Van Outen was 46.
She said: "Aah, she looks so sweet. She's actually the same age as my mum. I actually don't know what she does."
Barker went on to ask "Rachel Riley" - who is actually Pete Wicks and Sam Thompson pretending to be the Countdown star - whether she wanted to be a mother figure to her during the series, even though Riley is only 35.
Watch: Denise Van Outen and partner Eddie take laughter therapy
The series also includes Lady Leshurr playing as Big Narstie, Baga Chipz pretending to be Kim Woodburn, Melvin Odoom and Rickie Haywood Williams playing as will.i.am, and Loose Women pals Kaye Adams and Nadia Sawalha posing as Gemma Collins.
Charlotte Crosby will enter the series later on as Peter Andre.
Barker, Van Outen and James are the only celebrities playing as themselves.
In the opening episode, Van Outen was taken in by Wicks and Thompson, believing that she had formed a connection with maths genius Riley.
However, when players were asked to guess which of them had once soiled themselves live on TV, some of them worked out that Gemma Collins couldn't really be playing as she had chosen herself as the correct answer.
It was actually Blue singer James, who explained that he had had an accident while presenting the National Lottery draw.
The celebrities also got their first chance to rate each other for popularity, with Van Outen landing in last place.
Watch: Saffron Barker opens up on tough childhood