The Third Hokage is Jiraiya's teacher. I think he has portrayed a lustful old man from the beginning and he is also the first one that was defeated by Naruto's Sexy Jutsu. After the Third Hokage saw the Sexy Jutsu, his nosebleed just squirted out and he lost his consciousness. So Naruto stole the scroll of Forbidden Jutsu sealed by the First Hokage. After that, when the Third Hokage saw Sexy Jutsu again through the crystal ball, he said with no confidence, “it won't work for me... probably.” When hearing that Jiraiya used Perspective to peep at others, as his teacher, the Third Hokage even wanted to join him next time.