Prologue

Hiccup knew it was wrong in every sense of the word. But remained unable to resist her.

From the time he first saw her, she had looked so innocent and naive. So very, very untouched with her big blue eyes and angelic face. He didn't expect those youthful features to come with a body so tight and sinful. She was like heaven and hell combined, sent to earth to punish him.

He had been like an older brother to her in the beginning, watching over her, guarding her. He didn't plan out the forbidden affair that ended up developing between them once she started growing up. How could he have ever predicted it. It sounded so unreal even now.

The worst part of it was all the people he had betrayed.

His fiancée. His nephew. Her parents.

But at the end of the day, it mattered little.

Astrid made him feel an insatiable lust and burning he had never experienced before. Her small, slender frame was made to fit his. She hadn't just seduced his body but also mind and heart. She was his perfect match and he wanted to enjoy every bit of her for as long as the circumstances allowed it.

/-/

8:16

Astrid's parents kept quite busy as surgeons at the ER, often leaving their daughter to fend for herself for most of the day.

Astrid even liked it that way, it gave her a sense of independence. Her parents, however, were on a constant watch for a babysitter. Despite Astrid's protests, she was too young to be spending so much time by herself. She was only eight years old and it wasn't safe or recomendable.

Eventually after a long string of disappointments they settled for the sweet, amputated boy next door. Henrich seemed quite intelligent and responsible compared to other boys his age. He also had a cat named Toothless whom Astrid grew so fond of, she pestered her own parents into getting her a cat of her own.

"What should I name her?" she had asked Henrich when he came over to babysit her the evening after the cat was adopted. "Do you have any ideas, Hiccup?" Despite only knowing one another shortly, Astrid had already picked out a nickname for him. He didn't seem to mind it so she just went along with it.

'Hiccup' looked up from his phone to regard Astrid with a genuine smile. "What's the first word that comes to your mind?"

She pretended to think hard for a moment until her eyes widened with a mischievous smile. "Stormfly!" she exclaimed with a high-pitched giggle. Hiccup gave her a nod of approval. "Well, there you go!" he chuckled.

The remaining of the time Hiccup and Astrid spent playing Mario Kart while Stormly pranced around with Toothless. Astrid ended up falling asleep as soon as her parents made it home.

"Thank you again for looking after her, Henrich," Astrid's mom Evelyn said, pulling out her wallet from her bag to pay him.

"It's no problem Mrs. Hofferson," Hiccup shrugged, eyes lingering over Astrid's sleeping form on the couch. "Astrid is a good kid. I'm glad to be of help."

Dennis Hofferson stepped forward to give Hiccup a pat on the back. "We really appreciate it, son."

/-/

9:17

This time around Hiccup was asked to spend the entire weekend with Astrid.

"We know you would rather hang around with kids your own age," Evelyn mused. Hiccup let out an internal snort. "But it would be really helpful if someone stayed with Astrid while her father and I go on a conference. If the timing doesn't suit you, we could of course hire someone else," she added with a smile. "We just thought since Astrid is so fond of you-"

"I would love to," Hiccup interrupted her with a laugh. "Really, it's no problem. Astrid is like family to me at this point."

Evelyn clapped her hands together enthusiastically. "You are a really good boy, Henrich. Thank you. Astrid will be over the moon when she hears this."

Hiccup nodded, imagining the Hofferson girl's reaction. She would probably want to do movie marathons and play video games the whole time. Not that he minded. Truth was, Hiccup didn't have much of a social life anyway. He might as well hang out with the girl he had come to love as if she was his own sister.

/-/

When the weekend arrived, Astrid was wearing her blue and yellow dragon onesie and they spent the first few hours drawing. Hiccup being a hobby artist, didn't mind this activity much.

"Don't you have a girlfriend, Hiccup?" Astrid asked out of the blue, in the blunt manner kids usually did.

Hiccup gaped at her in mock-horror. "Why? Are you asking to be my girlfriend, Astrid?" he teased her.

"Nooo!" she giggled, face twisting in disgust. "I'm asking because it seems like you are lonely. I never see you with any friends. Don't you have friends, Hiccup?"

His smile slipped. "I..." he just shook his head at her. Great. He was being called out by a nine year old girl now. "I do," he knew it sounded forced but it wasn't as if she would be able to tell the difference anyway.

Luckily he didn't have to dwell on it for too long since Astrid's attention span seemed pretty short and the subject changed over to his doodles.

/-/

As night began to descend, Hiccup helped Astrid to her bed. "I'm still the bestest at Mario Kart," she stuck out her tongue at him.

"Bestest isn't even a word, silly," Hiccup rolled his eyes at her playfully.

"Yes, it is," Astrid argued. "You are just a big sore loser."

Hiccup's smile fell at this. He knew Astrid was only joking but it was something he was too used to hearing from his peers, especially from his cousin Scott.

"You are mean," he half-joked, making Astrid immediately guilt-ridden.

"Hey," he felt her small hand pat on his shoulder, "I was just kidding, You are not a loser," she tried apologizing.

Hiccup decided to feign a hurtful expression. "I don't know if I believe you."

"You should!" she tried to convince him. "You are the most amazing and awesome friend I have!"

"I'm the only friend you have Astrid," Hiccup laughed.

"Still, it counts!" she smiled at him with mirth in her eyes. Hiccup gave in at last, expression softening. "Alright, alright!" he exclaimed.

Just as he moved to leave, Astrid suddenly leaned forward and kissed him on the lips chastely. It was the familial type of kiss she probably gave her parents, but it still took Hiccup by surprise since he wasn't used to physical affection. He tried not to overthink it though. She was just a kid and she thought of him as her family.

"Sleep well," he said, before taking off.

He continued to receive goodnight kisses from her in later events, and realized he would eventually have to set up some boundaries when she is older.

/-/

10:18

Mere months from graduating high school, Hiccup was getting ready to leave for college.

He still watched over Astrid from time to time but it was getting less frequent now. Their friendship continued on though, and he relished every moment of it.

"You are my favorite person in the world, Hiccup," he heard say during one of his last stays. "You are not leaving, are you?"

Hiccup sighed. He knew he had this coming but was still not prepared for it. "I'm sorry, Astrid," was all he ended up saying.

She didn't reply at first, her bottom lip quivering with unshed tears. "All the other kids think I'm bossy and annoying. You are the only real friend I have," she sniffled.

Hiccup pulled her into a bear hug. "It's true I'm leaving for a few years but I will come to visit, and I will never stop being your friend, okay?"

She nodded, though still uncertain. "Promise?"

"Promise."

/-/

As Hiccup bid his old life goodbye for a brighter future, he briefly wondered just how much could change in five years.

Turns out.. quite a lot.

For when he returned back, he quickly discovered he was not the only who had grown up.

The next time he saw Astrid Hofferson she was no longer the ditzy little kid he used to babysit, but a beautiful teenager with a wicked mind of her own.

AN: Future chapters will be rated Mature for explicit sex and language.

Astrid counts as a minor as long as she is under 18. Hiccup is 8 years her senior.

Sequels for Shameless are in progress.