Jaime's whole visit to the Frey camp is hilarious. He strolls in like a boss, interrupts Lord Ryman, and explains the small flaw in his brilliant plan to him (paraphrasing):
Frey:I told the Blackfish that if he did not surrender, I would execute his nephew, but he refused.
Jaime: So you killed Edmure Tully.
Frey: It worked with Lord Mallister — he gave in within hours after they threatened to kill his son. But Brynden Tully is impossible to reason with!
Jaime: So, clearly, you had to kill Edmure Tully.
Frey: I can't kill him! He's the only leverage I have!
Jaime: Only a fool threatens to do what he is not prepared to do. If I threatened to hit you if you opened your mouth again, and you dared to speak, what do you think I would do?
Frey: Ser, you do not underst-
- Then he deposes Ryman, sends him home, and tells his son Edwyn that he's now in charge, provided he tries not to be as much of an idiot as his father. It seems like Jaime's picking up the Lannister awesome/funny slack while Tyrion is busy being all drunk and depressed.
- When Jaime tells Edwyn Frey to do a better job than his father, Edwyn's response is pretty funny as well:
Woman: I'm the queen.
Jamie: My sister will be surprised to hear that.
Woman: Lord Ryman crowned me his very self. (shakes her hips) I'm the queen o'whores.
Jamie's thoughts: No my sweet sister holds that title too.