Davos Seaworth (Liam Cunningham) noticed Jon Snow (Kit Harington) staring at Daenerys Targaryen's (Emilia Clarke) "good heart," and was in favor of the idea of a regal hook-up between Game of Thrones' King in the North and the Mother of Dragons. That finally happened in the Season 7 finale. He's not aware of it yet, but presumably he'll still think it's a good idea — but what about when they find out they're aunt and nephew, which will inevitably happen? What will Davos think then, and how does he think Jon and Dany will react?
"I'm very interested to find out...the expression on both of their faces when they find out that they're actually quite closely related," Cunningham says.
He's adamant that he doesn't know anything about what's going to happen, because he hadn't see any Season 8 scripts at the time of this interview, but he does note that "interfamilial closeness" isn't as big a deal in Westeros as it is in our world, and speculates that Daenerys may be more upset to find out that someone else has a stronger claim to the Iron Throne than she does. Jon, after all, is the firstborn of Rhaegar Targaryen, who was the firstborn of King Aerys Targaryen, which means that Jon is ahead of Daenerys in succession.
Of course, that's presuming that Jon wants to be the King of the Seven Kingdoms, which he pretty clearly has no interest in. He'll probably defer to Dany on that one. But maybe if they get married they'll rule side-by-side? Or maybe Dany will decide she doesn't want any challengers.
Don't look to Liam Cunningham for answers, though. He doesn't know.