Board Thread:TV Show Discussion/@comment-29740399-20161120013107/@comment-28895263-20161124015126

I do think that she would be anti-incest: the only family member she knows is Viserys (ewww....).

But Jon is another story. At the moment, they don't know that they are related. (Only Bran, and Howland Reed know.)  And they weren't raised together. It's possible that they will never find out. There's nothing to trigger sibling chastity.

History... we see books in GoT, we see libraries. Both Tywin and Eddard are seen consulting "A History of the Noble Houses of Westeros" (close enough title). Why wouldn't somebody like Illyrio Mopatis have a library, and make it available for the education of his Targaryens-in-exile guests? Surely such a library would have a history of Targaryen rule.

Jon, aware or not of his Targaryen blood, has no interest in the Iron Throne. He's never been south of Winterfell; his focus is on the war between the living and the dead. He will form an alliance with Danerys, with or without marriage, in order to gain men for that war: 100,000 Dothraki. For that, he will pledge fealty to Daenerys, and won't challenge her claim to the throne.