Gavin and Stacey star reveals extreme measures she went through to keep her character's return to finale secret

Warning: Honking massive spoilers for Gavin and Stacey: The Finale to follow.

That was pretty f**king brilliant, wasn't it?

Five years ago Nessa (Ruth Jones) got down on one knee and proposed to Smithy (James Corden) right at the end of the previous Gavin and Stacey episode, which cut out before we got to know what his answer was.

Returning half a decade later for one last episode, viewers were more excited to see what Smithy's answer had been than they were for their Christmas presents and it was all wrapped up in a stonkingly good final episode.

It turns out that Gavin and Stacey stuck the landing brilliantly, with fans adoring that last-ever episode and reckoning it wrapped everything up in style.

Except of course for whatever the hell happened on the fishing trip, but in this case, whatever each fan can imagine it being is better than getting a definitive answer that takes all the imagination out of it.

With the burning issue of what answer Smithy gave to Nessa hanging over the final episode, one Gavin and Stacey star had to go through some rather extreme measures to keep her presence on the set a secret to avoid giving the game away.

We are of course talking about Laura Aikman, who plays Smithy's fiancée Sonia, since her being in the final episode would make it clear to viewers that Smithy hadn't married Nessa after all, otherwise she wouldn't be around.

There's a big reveal early on in the episode where Smithy goes to meet his bride-to-be and it's Sonia, leaving millions of Brits watching at Christmas realising that he didn't accept Nessa's proposal, though she managed to avoid anyone else knowing she'd proposed with some impromptu Cossack dancing.

Taking to Instagram, Laura Aikman posted a video of her own family reacting to the big Christmas reveal, and either acting ability runs in the family or they genuinely didn't know she was going to be in Gavin and Stacey again.

"I take an NDA very seriously," she captioned the video, and on her Stories she shared a post from episode director Christine Gernon, who explained how they kept things so secretive.

"Laura Aikman spent the whole G&S shoot being hidden away," the director posted.

"Staying in a different hotel, not allowed to come to wrap or screening parties so no one knew Sonia was back.

"Such a great reveal. And she's amazing as both actor and person."

That final episode all led up to Smithy and Sonia's wedding, featuring a brilliant performance by Neil the Baby, though he didn't tie the knot after everyone he knew (and a couple of people on Sonia's side) and loved told him it was a massive mistake.

Everyone had been telling Gavin (Mathew Horne) he had to say something and right at the last moment he did, though in the end, it was Mick (Larry Lamb) that Smithy needed to tell him he was making a mistake.

Rushing off to stop Nessa from heading out to sea, Smithy managed to get there in time to propose, with the show closing on their wedding and a montage of some of the great moments from Gavin and Stacey.

James Corden revealed that the episode's final moments were the last thing they shot as he told a Q&A at the premiere: "The first schedule of the show had us finishing, I think it was going to be me on my own in a car on a low loader and Ruth and I were like 'that can't be the last day!'

"And I think that's the only time we've gone 'we'd like to have a say in the schedule here', and it was all to do with people's dates.

"This is a massive cast who are all very busy and have different things to do and have juggled a lot of things around to do it, but we really, really felt that the last day should be the last scene and that the last line should be the last thing that we ever shoot."

Ruth Jones opened up on the emotional final moments of the episode where Smithy and Nessa finally got together.

She said: "It was lovely because it did feel like a real wedding, didn't it?

"Like a real wedding to sort of pub reception and we were very grateful to being indulged, for being able to do that because it made such a world of difference that we did that last shot.

"And then Chris, when she called cut on the very last take, arranged for the sound department to play 'Run' and that got us all going."