When the eyes of two people, of the opposite sex, meet and linger on each other for a period of time. Only implying a certain amount of attraction. Eventually your eyes will drift apart but only to be caught gazing at each other only moments later. Some eye-looky sessions only last minuets or even seconds, but in other cases, eye-looky could go on for hours. Either way, the eye-looky attraction happened, and you know it, because the feeling is indescribable.
girl: "hey, did you see my boy and i playing eye-looky in the hall today?"
girl's best friend: "duh. how could i have missed it, you two were going at it for like 5 minuets."