The co-stars were just as creeped out by Sunday's finale as the rest of us.
WARNING: Game of Thrones spoilers ahead!
Jon Snow and Daenerys Targaryen may have been in the dark about their relationship during their steamy sex scene on Sunday's season seven finale of Game of Thrones, but stars Kit Harington and Emilia Clarke were just as creeped out as the rest of us.
The pair opened up about the big finale twist -- that Jon's real name is Aegon Targaryen, making him the heir to the Iron Throne and Dany's nephew -- in special behind-the-scenes commentary for HBO.
"For us, as actors, it's just weird," Clarke shared. "The reality of what they are to each other, I don't know how that's going to... I think [gags] might be the reaction."
"I think they both know it's wrong. I think they both know it's going to cause problems," Harington added. "But it's that thing, when you suddenly feel that deeply about someone and you go through those events together, it's like a runaway train. You can't stop it from happening."
Isaac Hempstead-Wright, whose character, Bran, had the unfortunate task of revealing the familial connection in voice-over during Jon and Dany's sex scene, is concerned with how this new piece of information will tear the show apart.
"This whole thing that started off Game of Thrones, the King's Rebellion, was a total lie," he said. "I'ts kind of like, mad, and what's going to be interesting is for Bran, it's like, 'What am I going to do with this?' because just as everything was coming together, everyone is coming together to fight, inevitably Game of Thrones will tear us apart."
"It's dangerous for everybody involved. I'm sure it's good for both of them in the moment, but you don't even get the relief of how beautiful it could be or should be," Peter Dinklage chimed in, after his character, Tyrion Lannister, was shown witnessing Jon and Dany shacking up in the finale. "It's, 'Oh. Just, it's not good.' It should be, but it's not. It's Game of Thrones. There's a long history of romance not ending well on this show."
In truly poetic (and potentially gag-worthy) fashion, Sunday's season finale introduced another case of incest just as Jamie and Cersei Lannister appeared to finally go their separate ways.
See what Nikolaj Coster-Waldau told ET about the Cersei's pregnancy reveal in the video below.