Jack looked over the boy's shoulder to see what he was doing. Mapping. How boring. Jack had run into him two weeks prior, in the literal sense that had Jack clutching at his side in pain as Hiccup and Toothless wondered what it was they seemed to hit into in the middle of the clouds. Jack had seen dragons before, but if he recalled correctly, they practically never ventured out this far and especially never traveled with people. Because of this and a couple other reasons he wasn't ready to admit to, Jack had taken an instant interest in the nameless, dragon-riding guy, but unfortunately wasn't able to immediately find out more because it was so easy to lose sight of them in the clouds.
Two days ago, he'd stumbled upon the pair a second time in a nearby village, and Jack had been hanging around ever since. Okay, so maybe he felt a little bit like a creep, but he couldn't help himself, he was just curious about this obviously unique person. Besides, it was less weird to be in the room with a guy who talks so much to his dragon friend. Although, it was almost creepy how the dragon seemed to intelligently understand every word that the boy uttered, and even some that he didn't.
His attempts at justifying hanging out with a person who couldn't see him were suddenly interrupted when he noticed that Toothless, the dragon whom the boy would talk to endlessly, was staring right at him. Jack stepped aside, waving his hands to see if Toothless' gaze would follow, and low and behold. Toothless could see him. Jack grinned in excitement, walking semi-cautiously over to Toothless. He wasn't exactly sure what to do or say, -he'd never actually tried talking to a dragon before- so he just landed on squeaking out a "Hi?"