Kurt doesn't blush, exactly- and he carries off the nervous laughter more smoothly than, say, a certain Ferelden fellow. He's not embarrassed, so much as simply surprised. And flattered. His gaze may be hard to read, but his body language is an open book once you've studied it for a few minutes. Possibly something he's gone out of his way to do, attempting to counter-act his frightening appearance by making his personality as visible as possible.

"Well, I would hate to be the cause of someone's fall. I'm far too inclined to catch falling people, it would get tiresome after a while."

Ok, so he's not that smooth. But at least he's pretty.