The latest evictee of the series was due to make his appearance on the spin-off show but never turned up.
And according to host Rylan Clark-Neal, no one had any idea where he was.
Instead, a member of the audience stepped in to take his place.
At the start of the show, Rylan told cameras: "Finally we were supposed to have Calum Best on, but we genuinely don't know where he is. This ain't even a gag. This really ain't.
"So, I had a little thought and thought who could I put in Calum Best's place tonight? It's got to be someone quite close to him. So, I love her and I think she deserves this so please be upstanding for our very own Barbara."
Calum was evicted from the show on Tuesday night after polling the fewest votes in the final vote. Lines had frozen and Calum was the least popular of the then seven finalists at that point.
After leaving the house, All Star housemate Calum told Emma Willis in the live show: “It hasn’t been tougher with the people, it’s been tougher with what Big Brother brought to the table.
“The first time round, I quite guarded, this time I wanted to be more open but I’m not a great people person.”
On being evicted before the final, he added: “I’m sad to come out now but they are all very worthy opponents (in the final).”
He later tweeted: "Been an amazing ride #CBB TBF can't wait for the real world ✌🏽️YES! #CBBCALUM"
Celebrity Big Brother and Bit On The Side continue nightly on Channel 5.