Don't plan to F w/ me.
LOLOL!
That is the infamous “inscrutable stare”.
It never means “a good thing” and is the prelude to The Stalk..
They will literally stalk their victim in slooooow motion so as not to alert or alarm them...the last foot or two, however, is another story...that ends with an explosion.
http://www.youtube.com/watch?v=YlI8qi75G_I
And that gal was just playing with her bud...:)
This one has down to near ballet perfection.
http://www.youtube.com/watch?v=MZHWsmkNkw4
[and yes, it’s creepy as hell when they do it to *you*, even if it’s only “in fun”....;D