When Kit said Jon might just have a dirty/kinky/inappropriate reaction to finding out Dany is aunt, this is the first thing that came to my mind… A great example from ACOK regarding how the Northerners view incest (though it’s a term they only use for parent-child or sibling dynamics in this world)
While tearing apart a bird with fat fingers, Lord Wyman made polite inquiry after Lady Hornwood, who was a cousin of his. “She was born a Manderly, you know. Perhaps, when her grief has run its course, she would like to be a Manderly again, eh?” He took a bite from a wing, and smiled broadly. “As it happens, I am a widower these past eight years. Past time I took another wife, don’t you agree, my lords? A man does get lonely.” Tossing the bones aside, he reached for a leg. “Or if the lady fancies a younger lad, well, my son Wendel is unwed as well. He is off south guarding Lady Catelyn, but no doubt he will wish to take a bride on his return. A valiant boy, and jolly. Just the man to teach her to laugh again, eh?”
The Northerners are really weird folk & not half as perfect as their fandom presumes them to be!