BBC Gavin and Stacey star films family's shocked reaction to appearing in finale after 'taking NDA very seriously'

Gavin and Stacey returned to our TV screens for a final time on Christmas Day.

Five years on from the last special, the BBC revealed nuggets of information about who will appear in the finale and what the plot would be, but there were many surprises squeezed into the 90-minute episode.

The episode began with the characters preparing for a wedding, which fans assumed (or hoped) would be Nessa (Ruth Jones) and Smithy (James Corden), as she proposed to him at the cliffhanger ending of the episode which aired in 2019.

But unfortunately for viewers across the country, Smithy was marrying Sonia (played by Laura Aikman), his girlfriend from five years ago.

And the broadcaster managed to keep this union very, very quiet in the lead-up to the show being aired - going to extreme lengths to hide Laura's involvement.

James Corden, who co-wrote the show with Ruth Jones, revealed that Laura stayed in different hotels to the rest of the cast and set off to work in the middle of the night to avoid being spotted by the press.

Corden paid tribute to Laura and explained: "She stayed in different hotels. She was going into places in the dead of night. She's not part of any of this, such is her want to try and protect it."

She didn't even tell her parents, and she filmed her parents reaction to her appearing in the episode.

Laura posted the hilarious clip on social media platform Instagram with the caption: "I take an NDA very seriously".

When her mum spotted Sonia on screen, she screamed and pointed at the TV in disbelief, before clutching her face and shrieking "Oh my god!".

On the video she has typed: "The moment my family realise Sonia is ruining Christmas again".

Fans have flooded to the comment section to admit that they reacted in a