Washington and Hawke occasionally hold their mouths in the exact same dopey but contemplative position, usually while absently gazing into the distance. Drop your jaw 3/4" while holding your lips together and sucking on them slightly - that's the look. They're the only two I can recall doing this. I think Ethan picked it up from Denzel and uses it in all his roles.
shareFunny you mention that. This is Denzels signature face. Your description is exact. What the heck?
shareThis is almost, but not quite, what I'm talking about -
http://i.dailymail.co.uk/i/pix/2014/05/27/article-0-1E3ADE6A00000578-415_634x391.jpg
Totally agree! Sometimes I do the Denzel suck-cheeks and cock my head to one side while eyeballing someone just for my own amusement.
Hawk has been doing it for a while, even in Before Sunrise. His is slightly different, more like the early Bruce Willis side-pout.