1) If a man is hungry, do not talk to him, do not take offense at his grumbly-ness. Just smile and nod, and get him some food STAT. After he eats he will turn from being a bear into his nice normal self. DO not be alarmed at this transformation, it just happens, it is weird, but normal. This also pertains to small men of all ages. If they are grouchy, feed them.
2) If there is a tech device in hand, he cannot hear you. There may be nodding, may be some "mmm-hmms" but he does not hear you. This is your chance to say very strange things to him...and chances are they did sink in and he will later ask you "Did you say that the alien invasion is happening at 11:13 tonight and that they are coming to take away my underwear?" and you can reply with big innocent eyes, "NOOO, of course I would never say anything so weird, are you ok?"