A head-shake in the negative, as really...he didn't have anything to say. It was more just a general comment on the state of things, that noise of frustration. Rare though it was. Quiet for a bit longer, then speaking.

"Promise me." Taking his time, to try and think about how to phrase things. "Promise me you won't put it off, that we won't put off talking. There are things that need discussing, before it gets too late." Even if now was not the time to discuss them.