"You must be curious about my source?" Ludwig understood why the mood of his cousin had soured.
Ludwig knew too much, and he didn't bother hiding it in order to pressure Amir through his information source.
Which worked perfectly, as Amir wondered how this man knew so much about him and why, while Amir himself didn't see a thing on his own end.
It's not like Ludwig had been blind to the problem, and he understood that it would come to bite him in the back in the future. It's why he had given Sarlen full right to expose some of the secrets and relationships he had built in the world. All in an effort to hint that the two sides had nothing to hide.
But that was the problem here, the only thing Amir heard was the good stuff, he didn't find any weakness that might make the two sides equal. Or so misunderstood Ludwig.