Sansa is now in the unlucky position of having to cover up for Petyr Littlefinger's murder of her aunt Lysa. If she doesn't go along with this Petyr will probably end up dead and where does that leave Sansa? Also she is somewhat grateful that Petyr saved her from being murdered by Lysa, and apparently not clever enough to realise (or perhaps the truth is too terrible to contemplate) that he arranged that by kissing Sansa in full view of Lysa.
Everyone seems to agree that the various lords of the vale aren't going to be too happy with Petyr being in charge of the Eyrie. So he invites one of them up (Nestor) and flatters him into thinking that Lysa wanted him to inherit the castle at the bottom of the mountain that protects the approach to the Eyrie. He also makes sure (with some confusion over signatures) that Nestor has a vested interest in Petyr continuing to be in charge or the Eyrie. So that bit of the nine dimensional chessboard is sewn up. Meanwhile Sansa must continue to pretend to be his daughter, and the horrible little Lord Robert thinks of her as his new mother. Good grief what an unpleasant and dull existence. To think Sansa at one point thought she was going to be married to a handsome and chivalrous king of Westeros.
It's almost certain that Petyr is heading for a fall. And it will be a big one. But what is his next move?
