#1 - do you mean in the sense of someone who is courteous, or well-mannered, or genteel? Or are top hats and tails involved?

#2 - a few options would either be: if walking close behind, speed up and pass, giving a "good evening, excuse me" when drawing near to telegraph proximity; or carry on a cell phone conversation, read a book while walking, or something similar that indicates his attention is elsewhere, i.e., not on her in any way that could be construed as anxiety-inducing.