Well nobody was expecting that!
EastEnders fans were shocked on Monday night when a familiar face appeared on screen.
The BBC soap has aired spin-off Secrets From The Square on Mondays, to make up for a lack of episodes.
And fans were shocked after Natalie Cassidy's fiancé made an unexpected cameo.
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Crew member and cameraman Marc Humphreys works behind the scenes on the show, and is engaged to to the long-serving actress.
Natalie has played Sonia Fowler, formerly Sonia Jackson, on the show since 1993.
She's been part of EastEnders since she was 9 years old.
Adam Woodyatt, who plays Ian Beale, pointed out Marc joking, "We can't stand Marc! We have to be nice to him because he's with Nat."
But despite this, some fans had no idea that Natalie's husband-to-be worked on the show.
They took to social media to share their surprise...
In Monday's episode of Secrets from the Square, Adam Woodyatt and Letitia Dean sat down to reflect on their careers.
'Sharongate' revisited
One of Letitia's most famous storylines has been named 'Sharongate', and it's gone down in soap history.
It resulted in a shocking moment from 1994 where Sharon's secret affair with brother-in-law, Phil Mitchell, was revealed to the entire pub.
Secrets from the Square has kept EastEnders fans occupied with plenty of nostalgic moments.
The first episode saw Stacey Dooley talking to Albert Square icons Kellie Bright and Danny Dyer, who play Linda and Mick.
And next week we'll see Davood Ghadami and James Bye speaking about characters Kush and Martin.
BBC One will air EastEnders: Secrets from the Square, hosted by Stacey Dooley, at 8pm on Mondays, while classic episodes of the soap will air at 7.30pm on Tuesdays.
