Sophie Turner explains why it was 'vile' to kiss 'brother' Kit Harington in new gothic horror film

Sophie Turner has revealed the reason why her on-screen reunion with Game of Thrones co-star Kit Harington was a rather awkward experience.

The 29-year-old shot to fame for her role as Sansa Stark in the HBO fantasy adaptation alongside Kit Harington, who played her half-brother (later revealed to be cousin) Jon Snow.

After spending eight years filming together, the pair were, of course, happy to be back on set with one another for their upcoming film The Dreadful.

Few details have been given away about the film, which is set during the War of the Roses, other than the fact that Turner plays a character named Anne and Harington will play Jago.

Anne lives on 'the outskirts of society' with her mother Morwen (Marcia Gay Harden) during this tumultuous period of English history, with the pair visited by a figure from their past.

Incest is no big deal for Game of Thrones characters with the surname Targaryen... (HBO)

It all sounds wonderful and brooding, right? Unfortunately for Turner and Harington, there was only one obstacle between them and the perfect on-screen reunion.

The fact that their characters share multiple x-rated scenes in The Dreadful Turner opened up on the moment she realised that she and Harington would be exploring a very new on-screen dynamic in the film during a new interview with Seth Meyers.

"I got the script for this amazing gothic horror," Turner explained.

As a producer on the film, Turner was asked by director Natasha Kermani for her input on casting, to which she suggested Harington.

"I sent the script to Kit and he said, 'Yeah, I'd love to, but this is going to be really f**king weird, Soph." she continued.

"I was like 'what is he talking about?' and then I'm reading it and I'm like 'Kiss, kiss, sex, kiss, sex . And then I'm like 'oh shoot, that's my brother'."

...but not for Kit Harington and Sophie Turner (Olga Gasnier/WireImage)

Of course, the pair aren't actually related, but when you consider that Turner and Harington were 15 and 24 respectively when filming commenced and spent close to the next decade growing up together, it's understandable why the pair would feel a little icked out.

Ultimately, the power of a good script was enough to win Harington over, and he signed up for the role.

So what was it like to get it on with your fictional sibling? 'Vile', according to Turner.

"We get on set and it's the first kissing scene and we are both retching," the Joan actor revealed. "It is vile. It was the worst... another really bad moment in my career."

Fortunately, the pair were able to get over the reservations and wrap filming The Dreadful, which is currently in post-production.