All Hiccup ever wanted to be was a dragonslayer to prove his worth as a Viking. He thought learning from the dragons would help better his society and the understanding of the world around them and the creatures inhabiting it. But now, here she is doing something wholly unnatural and taking in a massive cock in her mouth. “Mmmgh…”
Feeling the lips wrap around his shaft, the night fury grunts, pushing his hips forward. The massive thing slides deeper into the woman’s mouth, widening her lips to the point of pain. She places her hands on his thighs, pushing against him and grunting.
He grunts back but pulls away, letting her lean forward and cough, rubbing her throat. “J… just sit back, Toothless. I got this.”
Toothless falls onto his rump, his tail curling up behind her, pulling her in.
Hiccup smiles up at him, a hand wrapped around his cock as she lowers her mouth around the shaft, her cheeks puffing out, her throat expanding slightly. She continues to take him, softly humming as she slips up and down, slathering that dragon dick with her spit and tasting on it the cum of the night fury.
Toothless’s tongue rolls out, and he huffs, soft grunts turning into mighty roars as his cock flares and pulses. Soon, he gasps out in a hiccup of delight as a piercing shock rushes through the sky. At the same time, he erupts, his cum bursting out from him, spitting out of her mouth and throat and sending Hiccup coughing and hacking, soon having her face covered in a glaze of dragon jizz.
It takes her a few moments to catch her breath and wipe her chin, but she keeps hold of his length and looks up to him. “Hey, Toothless...” she says, licking her lips. Let’s fly away from here,  you and me.”
The dragon leans in, nuzzling against her cheek and growling possessively, pulling her in.
She wonders at that moment if she has a choice.
And she decides she doesn’t care if she does!
When Astrid arrives at the small bowl where the traitor and his pet will convene, she finds the cloak left behind by the one who had been Hiccup. She sniffs the air and wretches. The stench of the dragon is pungent here, much more potent, more musky.
When she heads towards the source, she sees the congealed pool of dragon jizz, splattered on the ground, and she grumbles. “They’re gone. Finally, life can go back to normal,” she says, spitting and marching back to Berk.
“Come home soon, Stoic. On the next voyage, I shall join you!
—
The woman holds onto her dragon lover, her naked breasts pressed against the strong, scaled back as he flies through the air. It isn’t long until he finds a place for them, among the beaches and the various islands surrounding the Viking village, and he throws her off with a mighty buck.
She lands on the sandy ground upon her back, grunting but giggling, smiling up at him.
“Oh, you’re hungry for more, are ya?” she asks, licking her lips. “That’s okay with me because I want more, too!”
She gets onto her knees when Toothless tilts his head, grunting, leaning in, and sniffing at her head.
“Ah… q-quit it, what are you…?
There is something odd in the air or perhaps something strange within the woman herself. She feels almost like she’s wearing something that doesn’t quite fit her and is in a daze.
She snaps out of it when Toothless presses his warm, wet tongue upon her cheek. She sighs in delight, letting him groom her, rolling her shoulders, and getting onto all fours.
This feels more natural as if she was always meant to be beneath the dragon. He climbs beside her, pressing his tongue to her cheek and slicking his tongue upward in a long, laborious lick.
It feels so nice that he’s taking the world off her shoulders, but more than that, he licks off a large portion of her hair, leaving her head smooth where he touched it.
“W… what the?” She squeaks, grasping at her bald head. She crawls over toward the beach to peer at the damage.
Toothless gazes at her, waddling away. Her crawl grows from an awkward stumbling, and her balance wobbling this way and that as her bones crack and she gains more maneuverability. Soon, she’s bounding, landing in front of the water and staring at the reflection within.
The image is distorted by the clam waves and her reflection, but her teeth seem too big for her mouth, grinding and growing. She blinks, and the once-round pupils open to reveal bright, slitted, and curious things.
Without being able to articulate words, she stumbles back, her rump bumping right into Toothless’s face.
“Calm, female,” he urges her.
“C-calm? How can I be calm!” She reaches up, patting around her mouth. Now that she can talk, she finally feels the muzzle extend into a broad snout, accommodating her teeth.
The warm and wet tongue of the dragon presses itself between her legs, massaging her womanhood, lapping up and down her lips and her slit.
She falls on her cheek, panting, smiling. “A… ah well… I g… guess I can be… ah… calm…!
Toothless growls in his apparent agreement, pressing that thick thing against her, pushing it deep into her tight hole.
“Aah… it’s… t-o-hoo thick!” she groans, grasping the ground. Her fingers dig into the sand, grabbing large chunks of the soil. When she relaxes her grip, she grasps again, only to have claws extend from her fingertips. Her hands explode into powerful forms, tearing up the ground. The sand exfoliates dead skin off of them, revealing beneath them jet black scales.
She throws her head back as his tongue pushes inside of her, spreading her out, but she doesn’t contract around it. No, her womanhood grows around it, her rear expanding with it, her legs filling in, widening, strengthening, holding up the new expansion to her body. Opening her mouth wide, she roars a mighty and predatorial cry that echoes throughout the islands.