Board Thread:TV Show Discussion/@comment-79.116.32.60-20160920154405/@comment-28895263-20160921051242

I'll concur that Petyr's lust for Catelyn / Sansa is second only to his lust for the Iron Throne.

But slapping Robin was a mistake, driven by emotion. The real evidence of a mature Sansa came a little later: after Petyr had killed Lysa. Sansa was able to lie convincingly to the other Lords of the Vale, and chose to do so by cool reasoning. Which made her even more desirable to Petyr, of course.

Petyr's ultimate goal is the Iron Throne. It was an alliance between the North and the Vale that took that Throne during Robert's Rebellion. It could work again. Petyr already has the Vale; offering Sansa to House Bolton was an avenue toward an alliance with the North. He may have heard that Ramsay was cruel; I doubt he knew that Ramsay was a complete psychopath. His intention was to gain the armies of the North through Sansa as Lady Bolton. That was "plan A".

That plan fell apart when he learned that Sansa had fled Winterfell, presumably for Castle Black. So he rode north with the Knights of the Vale with his "plan B": offering the Knights in support of Sansa and Jon's efforts to re-take Winterfell, and creating a debt obligation that way.

It almost did not work. Sansa was foolish in not informing Jon of potential reinforcements on the way; Jon was foolish in falling for Ramsay's trick with Rickon. Neither really deserves to rule after that. Petyr saved the day, but it was a near thing.

I can't believe that this was any kind of test. Plan A failed; Plan B worked, but only just barely.

Petyr wants Sansa as his queen out of lust, and out of a desire for the armies of the North. That Sansa seems to be learning how to play the politcal game, and lie when it's required, is a bonus. (Or not: Queen Sansa could easily poison King Petyr, and rule Westeros in her own name.)