Celebrity Circle catfishers Kaye Adams and Nadia Sawalha have thrown their competition into jeopardy with one too many mistakes in their impersonation of Gemma Collins.
Watch: Gemma Collins admits sex tape confession was 'big fat lie'.
Van Outen knows Collins well as the narrator of Towie and became suspicious when The GC repeatedly referred to her as "Dens" - a name she pointed out that she'd never heard her use before.
In a group chat between some of the players, Van Outen called out "Collins" on the strange nickname and tried to trip her up by asking when they'd last seen each other.
Adams and Sawalha tried to bluff their way out of the awkward situation by saying they couldn't remember either, but unfortunately Van Outen revealed it had been a very memorable occasion - a christening in Spain.
Rachel Riley - aka Pete Wicks and Sam Thompson pretending to be the maths whizz - then piled in to point out that during a quiz the night before, they'd outed themselves further.
The whole group had noticed that when they gave Amy Childs as an answer to a question, they'd managed to spell Collins' old Towie co-star "Chiles" instead.
Duncan James, who was the first celebrity to be blocked last night, ended his time on the show by visiting The GC where he discovered the player's real identity as Adams and Sawalha.
Tonight's episode introduced Charlotte Crosby playing as Peter Andre, who was much more successful at convincing the group that she really was the Aussie singer.
However, Saffron Barker managed to offend again as she commented: "My mum used to love him."
Players Gemma Collins (Adams and Sawalha), Big Narstie (Lady Leshurr) and Kim Woodburn (Baga Chipz) have all now been told that they have split off into a smaller group, The Triangle, which leaves them in danger of becoming the next blocked celebrity.
Watch: Denise Van Outen and Eddie Boxshall meet laughter coach, Pete Cann, in their new podcast, Before We Say I Do...