If looks could kill

This is a colleague of mine. He was standing on the platform waiting for the Metro, when I came. I walked right in front of him, was looking at him, without him noticing me. I placed myself half a meter from him, took out the camera from my bag, adjusting it and took one picture before he noticed "me" (he couldn't see who it was behind the camera). As he turned his head, I took this shot. When he recognised me he had to smile.

It's not cropped. I just made it B/W and adjusted the contrast.