Sansa and Tyrion are not having great dinner time converstaion.
Tyrion goes to see his dad. They get news that Robb and Catelyn are dead. Tywin is quietly pleased with himself for having arranged it all (so that's confirmed). Tyrion agrees with me that the Freys are not likely to win any friends like this and will now need Lannister protection. I don't think that will make the Lannisters look good.
Joff is being a tit as usual but it seems like he might get one of Tywin's lessons. So that should be entertaining.
The Dornishmen are still visiting for the wedding. Everyone is worried about Oberyn. Still, it's hard to see how this wedding can go worse than the last one.
We learn that GREGOR is the one who killed Dornish princess Ellia and her children (Rhaegar's wife; Dany's family). Tywin is going to blame it on Ser Amory Lorch, who is dead, though he may have been involved anyway, it's unlcear whether Tywin is lying or Tyrion just thinks he is. In any case Tywin allowed it to happen to win Robert's favour, since he came late to the cause.
GRRM has an annoying way of making the bad guys seem good: "Explain to me why it is more noble to kill ten thousand men in battle than a dozen at dinner."
We also know that Bolton betrayed Robb and helped the Freys. This might have been clear from the wedding chapter but a lot was going on and I did not follow who was who very closely. The Bolton's always seemed dodgy so that fits.
Tywin is hinting about some trick involving Renly's ghost. And that Littlefinger might know where Arya is. Tywin wants to marry her to Bolton. Oh dear.
Tywin still needs to get all Robb's former bannermen to join him. And get the North by getting Tyrion a son with Sansa. But Sansa is not going to be too happy with Lannisters...