Work Text:
In retrospect, Hiccup should have established firmer boundaries from the start.
But being a normal, healthy teenage boy, he had a robust sex life. Well. By himself, that is. With the raging hormones typical of a lad his age, Hiccup did nothing to keep his raw Vikingness contained.
Morning, noon, or night, the urge would come upon him. And ever the blacksmith, Hiccup was wont to strike while the iron was hot. Simply find a little privacy, and take care of his needs. Clear his head, so to speak. With a furtive tug and squirt.
The thing was, he'd always considered being alone with Toothless to be "privacy".
That's what people do, right? Now and then everyone has sex, or relieve themselves, in front of their pets. Animals certainly aren't shy about rutting out in the open. And at first, Toothless barely paid Hiccup's self-pleasuring activities any mind. If he looked at all, it was only for a moment, and then he went to sleep or found something more interesting to investigate.
Then one winter night, a sudden snowstorm forced Hiccup and Toothless to take shelter in a cave. Huddling for warmth, with little fuel to keep a fire, the two of them shared a pretty miserable night. It didn't prevent the Viking's regular morning erection, though. And having had enough of suffering with poor conditions, Hiccup didn't see the sense in denying himself any available comfort.
He jacked off as discreetly as he could in the dragon's embrace, and accidentally splashed a little on his best friend's foreleg. Toothless curiously licked it away. Hiccup blushed furiously, an odd fluttering in his tummy.
But from that moment, Hiccup began to notice Toothless paying more attention when he masturbated. He'd open his eyes and find the dragon watching him unabashedly. The Viking was embarrassed, but dismissed the dragon's interest as a phase that would pass soon.
Then one night, Hiccup woke late to an especially stimulating dream. He kicked off the furs on his bed and stroked himself to satisfaction, spilling his seed on his chest and belly. He sighed, trying to find the will to get up and grab his sock off the floor to wipe himself clean with. But he was too slow, and dozed off.
Hiccup was soon jolted back to the tickling sensation of a dragon's huge tongue sweeping over his naked body. He snapped awake, all of the muscles in his limbs spasming and locking. He gaped in horror as Toothless smiled his big innocent grin, and licked his lips.
Hiccup's face burned with humiliation, and his heart hammered. His impulse was to scream and throw a fit. But he stamped all that down, not wanting to frighten and shame the dragon. Instead, he gritted his teeth and pasted on a hideous rictus grin.
"So, uh... That happened," he stammered. The dragon's expression drooped with concern. Hiccup patted Toothless on the snout, and pulled a fur over himself to belatedly try to regain some modesty. "No, no... It's okay, bud. Just don't, uh. Don't do that again. Okay?"
The next few days, Hiccup could barely make eye contact with Toothless. And despite a baffling increase in randiness, he cut down on the self-pleasuring. Finding a way to ditch his best friend for the few times he did relieve himself. The tension was palpable, and the poor dragon looked distressed all the time. The other kids at the dragon-training academy asked if Toothless was sick.
This was untenable. Hiccup couldn't bear such distance between himself and his best friend. But when he was affectionate with the dragon, Toothless would boldly sniff at his crotch, and the Viking would get anxious again.
Finally, Hiccup reasoned that it wasn't so bad if the dragon wanted to eat his semen, was it? So long as he didn't allow his four-legged friend to bring him to climax, it was okay if he permitted him to lick up the leavings. It wasn't bestiality, then. Right? It was only grooming!
And so that night, after shooting his load, Hiccup softly called the dragon over.
"It's alright, bud. You can have it, it's yours," he whispered, trembling. The dragon happily lapped at Hiccup's glazed abdomen, and over his soft, spent genitals. His best friend made quick work of the mess, and purred while the Viking gave him a scratch on the chin. Then Toothless ambled back to his stone bed and dropped off to sleep quickly.
Hiccup didn't fall asleep so easily. It took a long time before his pulse returned to normal, and his face stopped burning. He could feel saliva dry tight against his skin.
But during the day, the tension was gone. Hiccup found he could interact with Toothless normally again, the dragon having received forgiveness. Toothless no longer begged for a treat, knowing it would come at bed time. The Viking set about trying to forgive himself, as well.
Eventually, Hiccup grew more secure with his decision, finding peace in his rationalizations and their mutual content. Hiccup even stopped blushing when Toothless crept close to the bed before he came. Watching with anticipation as the Viking's hand bobbed around the head of his cock.
Then one night Hiccup removed his hand early, inviting the dragon's tongue to caress his member just before it popped. And then, he started to put his hands behind his head and let Toothless do all the work. Silky wetness bringing him to erection, to orgasm, and back to shriveled depletion.
As soon as Hiccup had almost stopped feeling bashful and conflicted about this new escalation, the dragon started to become erect while he serviced his human friend. His red organ emerged from a slit between his legs. The Viking tried to ignore it, but Toothless looked so pathetic. Swallowing Hiccup's ejaculate, and twitching his hips uselessly, stabbing at the air. Hiccup would pull a fur blanket over his head and feel like the most selfish cad who ever lived.
Come on, now! He couldn't reciprocate, could he? Accepting favors was one thing, but to actually... No, it was out of the question. People simply didn't do that!
But, Hiccup was sure that Toothless was smarter than the other dragons, and was even coming to believe the Night Fury was able to properly understand human speech with a full vocabulary. Did that make him a person? The dragon's mouth was just incapable of forming words himself.
So after a couple of weeks of simmering in guilt, Hiccup could stand the pleading in his best friend's eyes and the desperation in his turgid member no longer. He couldn't bear to sentence his best friend to blue balls, and he had to return the favor. So what if it's bestiality? It was just polite!
One night after Toothless licked him clean, the Viking sighed and slipped out of bed to kneel beside him. He urged the dragon to roll onto his side, and Hiccup carefully closed his hand around the dragon's penis. It wasn't big; roughly equivalent in size to the Viking's own endowment. It was slick, weeping an oily lubricant from the moment it appeared, and Hiccup held his breath and pumped it. Toothless never lasted long before he finished. He would spurt a thinner and pinker emission than Hiccup's own, and the dragon would lick that up, too.
Taking in the radiant, satiated expression on the beast's face settled Hiccup's tumbling stomach, and within a few days he actually began to look forward to gratifying his friend as much as he looked forward to his own satisfaction.
As Hiccup and Toothless grew more comfortable, their livlier sessions produced position changes and experimentation, and the Viking discovered the joys of having his ass eaten. The dragon's long tongue could swipe his cock and hole at the same time, and Hiccup was reduced to a quivering heap. Eventually, he developed a ferocious desire to be filled.
"Oh, what the fuck," Hiccup grunted, "I'm going to Hel already. Just stick it in."
Hiccup got on his hands and knees and arched his back, wiggling his rump high in the air.
Toothless loomed over him and did what came naturally.