Warning: This article contains major spoilers for Gavin & Stacey: The Finale.
The return of Laura Aikman as Sonia was undoubtedly one of the latest Gavin & Stacey special’s biggest plot twists.
Laura played Smithy’s new girlfriend in the 2019 festive special, and left viewers shocked when it emerged early on in the finale – which aired on Christmas Day – that she and James Corden’s character were gearing up for their wedding.
After the episode aired, the former star of CBBC’s The Mysti Show revealed just how she kept her appearance in the award-winning sitcom so tightly under wraps.
During a pre-Christmas screening of the special, creators Ruth Jones and James Corden revealed that Laura had stayed at a different hotel to the rest of the cast during filming to avoid raising suspicion, and even swerved the wrap party to avoid being spotted with the rest of the cast.
On Christmas Day, Laura even disclosed that she had avoided telling her parents about her appearance in the episode, meaning her family found out about Sonia’s return at the same time as the rest of the nation.
“I take an NDA very seriously,” she wrote on Instagram, alongside a clip of her family watching Sonia’s first scene.
Laura wrote in a follow-up post that Sonia’s wedding dress had to be sourced on Facebook Marketplace, to avoid creating any speculation about her character’s return.
“Our costume designer Shan James [had] to alter it massively, as 48 hours before we shot the wedding it didn’t fit,” she told her Instagram followers, adding that she also had to wear a wig on set, as her own hair was so different because of another role she was playing at the time.
Gavin & Stacey: The Finale attracted a staggering 12.3 million viewers (not including those who watched it on iPlayer), making it the most-watched Christmas Day broadcast in 16 years.
Despite its popularity, Ruth and James have made it clear they won’t ever write any more, with the latter telling BBC Breakfast earlier this month: “It can’t carry on after this. We can’t see [how] it could – you’ll have to wait and see!”