[There are very few people in the world who can sneak up on Natasha, but Nate isn't like most people and for once she may have met someone who is actually on her level skill wise. Not that he would ever use his skills against her, but it does mean that for once someone is able to get within five feet of her without her noticing right away.]

Miss Romanoff.

[His voice is a deep pleasant baritone and he gives her a little nod in greeting. In person she'll notice two things right away: one is that he is extremely tall, six foot five, which makes the fact that he was able to go unnoticed extra impressive.
And two: He is dressed in a sharply tailored all black suit and is wearing black leather gloves, even though it isn't cold outside.]