Sophie Turner and Kit Harington both gag after filming passionate kissing scene for new movie

Kit Harington and Sophie Turner amused fans after filming an on screen kiss for an upcoming movie.

The pair played Sansa Stark and Jon Snow in HBO's landmark show Game of Thrones, and their reaction after acting out the scene has left people amused.

In Game of Thrones Sansa and Jon are siblings, or at least they believe they are at first - later it turns out that they're actually cousins as Jon is the son of Sansa's dead aunt that Sansa's dad raised as his own illegitimate son to conceal his birth.

I'd say spoilers, but it's been years now.

The actors are now starring together in an upcoming horror movie where they play a romantic couple rather than cousins, and a clip from production was shared on social media.

And the moment that 'cut' was shouted while they were filming a kiss scene, the pair immediately both retched.

In fairness, siblings to lovers is very on brand for Game of Thrones, what with the whole Jaime and Cersei brother/sister affair and Harington's character Jon Snow inadvertently sleeping with his aunt Daenerys, played by Emilia Clarke.

That's before we mention a certain Targaryen niece/uncle wedding in spinoff series House of the Dragon.

And many George RR Martin fans were left saying the same thing as they piled in to the comments to point out how in a weird way, it was fitting for Game of Thrones.

One joked: "Finally, Jon Snow embraces his true identity as a Targaryen."

Another wrote: "I guess there’s no debate on whether jon is Targaryen anymore."

Referencing the most infamous incest plot in Game of Thrones, someone else replied: "Cersei would be proud..lol"

Meanwhile, someone else suggested a more likely cause for the retching - the pair had played close family on screen for years.

"When you've been siblings for 8 seasons and your brains can't process the switch," they wrote.

Harington and Turner had been filming for a new movie called The Dreadful, which is due to be released on February 20.

The movie is a gothic horror set in 15th century England during the Wars of the Roses.

This was a period of civil war in which the Houses of York and Lancaster, both branches of the ruling Plantagenet dynasty, fought for their claim to the English throne, and ended with the death of King Richard III at Bosworth and the ascension of the first Tudor monarch, Henry VII.

Funnily enough, the Wars of the Roses are themselves one of many periods from medieval British history which George RR Martin drew from when writing Game of Thrones, being a possible inspiration for the 'War of the Five Kings' plot in the story.