The Dreadful is the name of Sophie Turner and Kit Harington’s upcoming horror film — and, apparently, an apt descriptor of their kiss on set.

Turner said on Late Night With Seth Meyers on Thursday, August 14, that it was “vile” kissing her former Game of Thrones costar for the film.

“We get on set, and it’s the first kissing scene, and we are both retching,” Turner said. “Like, really, it is vile. It was the worst. Another really bad moment in my career.”

But Turner has herself to blame, really, considering she got Harington cast.

“I just got this script for this amazing Gothic horror called The Dreadful, and I was reading through all the characters, and I’m producing it, so the director was asking me, ‘Who do you think?’”

Turner said her first thought for one character was Harington, who played Jon Snow, who was raised as the brother of Turner’s Sansa Stark, on Game of Thrones.

“And so I sent the script to Kit. He sent me a message back going like, ‘Yeah, I’d love to, but this is going to be really f***ing weird, Soph,’” Turner added. “And I was like, ‘What is he talking about?’ And then I was reading it, and I’m like, ‘Kiss, kiss, sex, kiss, sex.’ And then I’m like, ‘Oh, shoot, that’s my brother.’”

Written and directed by filmmaker Natasha Kermani (V/H/S/85), The Dreadful is a War of the Roses-set story in which Anne (Turner) and Morwen (Marcia Gay Harden) live a harsh existence on the outskirts of society. Harington plays a man from their past whose reappearance “set[s] off a sequence of events that become a turning point for Anne,” the logline adds.

“It was such a good script, that [Kit] was like, ‘We kind of have to do it,’” Turner recalled.

So Turner and Harington put the intimate scenes out of their head… and then that kiss happened. Turner told host Seth Meyers locking lips with Harington was even worse than being covered in cockroaches for her new thriller film Trust. “Yeah, yeah, it was,” she said. “I have to be honest. It was bad.”

Late Night With Seth Meyers, Weeknights, 12:35a/11:35c, NBC