At the Sheridan Food Pub in Shannon Airport The dark-eyed young woman with lustrous and long black hair sits across from a short-haired young man in a solid-grey tee shirt. Except for two arm-length tattoos, he is nondescript.   But the woman, whenever he speaks, throws back her head. Her very red lips spread wide, and her white, flashing teeth reflect an abrupt laugh. What’s more, her dark eyes glitter.   Is the young man really a master of wit whose bland, featureless face conceals a command of words? Or is this responsive young woman— for all of her apparent…