Gavin and Stacey viewer discovers they were part of ‘top secret’ twist in final ever episode

If you thought all of the revelations from the final episode of Gavin and Stacey were over, think again.

There's been the overenthusiastic extras who went off script, a bounty of behind-the-scenes secrets as well as a host of hidden jokes which we've all heard about since Christmas Day.

Fans have been devouring all of the details from the finale of the BBC show since it aired on 25 December, as the cast went to extreme lengths to keep the contents of it quiet before it aired.

Although the 12.2 million people who tuned in were left stunned by how the highly-anticipated Gavin and Stacey episode played out, there was one viewer who got an even bigger surprise while watching it.

That's because Sonia (Laura Aikman) was donning her wedding dress which she had flogged on Facebook Marketplace while stood at the altar next to Smithy (James Corden).

Aikman, 39, was so dedicated to keeping the storyline a secret that she didn't even tell her own family that she was returning to the show.

Director Christine Gernon explained that she was 'hidden away' throughout filming, stayed in different hotels and had to miss cast parties to keep the storyline schtum.

As she had to be so cloak-and-dagger, the London-born star couldn't exactly go wedding dress shopping to pick something out for Sonia's big day.

Sonia's wedding dress was procured from Facebook Marketplace (BBC)

So instead, the Gavin and Stacey gang had to get resourceful, while also doing their bit for the planet by recycling another bride's dress.

In an Instagram post shared on Sunday (29 December), Aikman discussed how she ended up with the figure-hugging gown.

And like a lot of brides experience, there was some last minute dramas with the dress which gave the costume team a huge headache.

Aikman explained: "We couldn’t go wedding dress shopping (because of the secrecy), so this was from Vinted, (it probably belonged to someone who watched the show!) Shout out to our costume designer Shan James who had to alter it massively, as 48hrs before we shot the wedding it didn’t fit."

James then responded in the comment section by sharing some further details about the lore of the wedding dress, explaining that the original owner had been in touch with her.

She said: "It was a pleasure to dress you, an absolute pleasure, even though it was a massive job altering that gorgeous dress for you. It was from FB Marketplace and the lady selling the dress thought I was ‘well dodgy’ when I was so secretive!! She messaged me on Boxing Day."

James then went on to reveal the contents of the message she had received from the excited viewer.

Aikman shared some snaps of herself in the gown on social media (Instagram/@lauraikman)

It read: "I just watched Gavin & Stacey and had the oddest feeling that was my wedding dress that Sonia wore - can I ask if that’s what you used it for?"

James informed the woman that it was, in fact, the same dress - as she was finally allowed to let the cat out of the bag after the show aired on Christmas Day.

She responded: "Hi there! I tried to find these messages yesterday so that I could let you know exactly that!

"I couldn’t say a thing as it was extremely top secret and I couldn’t take Laura to any shop incase she was spotted. You can now tell the world! I had to alter it quite a lot to fit her but it was worth it I think. She looked gorgeous, so thank you so much."

The viewer explained she was over the moon that her wedding dress had come in handy, while revealing that she recognised it due to its detailing.

She replied: "That is amazing, it’s my absolute favourite show! I had good bumps when I watched it!

"I noticed the panel in the back, Oh bless! This is so great I’m totally made up, thanks for letting me know. What a cool job you have too!"