[Moments like these are those wherein it's all he can do to keep Zero as his face. Suzaku's inclination would be to speak gently and to tease her (not unkindly), telling her how she shouldn't be concerned about him; it's anyone who might wish to do Nunnally harm that should be concerned! He has the will of her big brother on his side, and where Nunnally's involved, it means mountains are easily moved. But after all that's happened, it would be questionable how much of that would lose meaning to her. So instead, as Zero, he angles his head downward to watch that movement--more out of demonstrating he's doing as much than anything else.

He can't exactly hide the smile that surfaces despite his best efforts.]

I'll do my best to give you no reason for concern. And at this point, I'm fortunately not going anywhere. A local "musebox", at most.