Readers of the Farseer Trilogy - need something explaining (major spoilers)

I'm on Book 3 and Fitz has reached Jhaampe and they're all heading off to the Mountains to find Verity.

I don't get why Kettricken is so angry with Fitz. Hobb presents it as totally understandable with no real explanation and I have no idea why she's so pissed off with him. I've either missed something or not understood something - can anyone explain please?