As far as Hiccup knew his mother was the only one that could effortlessly walk across multiple dragon backs. While he’d leapt from Toothless before- straight up to avoid obstacles, he limited those kind of daring actions to his dragon. Now with Castiel looking at him with that smile and a challenge in her eyes he felt the desire to do so. “Toothless.” He patted the night fury’s smooth neck and while it was unnecessary Toothless knew the other dragons would do whatever for the boy that brought about this paradise for them. So when he called out across the snowy village, dragons ascended in the dozens- not at all put off by the request.
Hiccup clicked Toothless’ tail fin to the other gear and straightened to his feet. “See you don’t know what your getting into Castiel.” He teased “I am the master of these sort of things.” Toothless gurgled down a laugh and resisted the urge to buck him off as the countless dragons drifted around them, clicking their calls of excitement and rumbles of pleasure.
He cautiously made his way across Toothless’ wing who decided now would be a good time to tilt- just slightly. Causing Hiccup to slid forward into Castiel and the two of them to land on Cloudjumper who had come at Toothless’ direct call, humming with amusement as the young Vikings. “Oh, uh…” Hiccup had caught himself, hands braced at either side of Castiel. Realizing how close he was, he was immediately on his feet. “Sorry. I’m not- um-” Awkward. He tried again. “Yeah, that was… I‘m just going to go then.” He turned heel, walking off Cloudjumper to drop down onto the wing of a nightmare and then pulled himself up onto a nadder which preened for his attention. He shushed it “trying to hide in a mass of dragons here, don’t give me away.” And gave into it anyhow, scratching behind its crown of spines.
Toothless grumbled as his plan backfired.