Loki was the third child of Laufey. He was unexpected, and very small, and at first no one thought he would live. But the little prince grew nonetheless (if much less than everyone else). And as he did, he also grew increasingly adorable.
He had long dark hair, a rare trait that he shared with his mother, and delicate markings that shimmered in the right light. What he lacked in size, he made up for with cleverness and magic, and soon the people did not care that he was not nearly the height of the brothers. They called him the treasure of Jotunhiem, and all adored him.
His parents and two grown brothers were extremely protective, despite that there were none in Jotunhiem that would hurt him, and also despite that even if there were, he was more than capable of handling it himself. Still, though he was coddled, his childhood was idyllic.
And then Farbauti died. She was killed in an avalanche, buried alive and crushed by rock and ice, when Loki was only ten years old. It was a growing problem since the Casket was taken, this crumbling of their world, and some said Laufey went slightly mad at the loss of his mate—certainly he became even more obsessed with keeping Loki safe.
Loki was rarely allowed out of the palace after that, and never without Laufey or one of his brothers. These restrictions would have been hard on anyone, but they were nearly impossible for Loki. The more restrictions that Laufey placed on him, the better he became at getting around them.
He learned to shape-shift, then he learned to make illusions of himself and to become invisible altogether, or even teleport. Loki managed for years to go off exploring with no one the wiser—he even visited Asgard and Svartálfaheimr, he feasted with the Dark Elves, he competed with the Dwarves.
It was a perfect solution. Laufey thought that Loki was safely sequestered in his room, and Loki got to do whatever he wanted.
And then he got caught.
He was seventeen, and it was the first time he had any interest in the mating season. He was too young to participate by any Jotun standard—they typically did not reach sexual maturity until twenty at least.
But Loki had no interest in 'typically,' and he was curious. So he lured one of his father's young warriors to one of the armory rooms. His name was Bynier, and Loki was so distracted as the larger Jotun pressed him down and kissed him that he forgot to ward the door against any unwanted visitors.
His brother Helbindi walked in just as Bynier was sliding his hands beneath Loki's loincloth. It was very unfortunate timing for Bynier—Helbindi ripped him away from his young brother and then dragged the horrified guard before his father.
Loki was fairly certain his father only banished Bynier, but no one ever saw him again. The message was clear enough. No one was going to dare touch the youngest prince again.
But Laufey knew he could not punish only Bynier. He realized he had been blind to Loki's willfulness—that he had obviously been too lenient.
"I'm sorry, you're going to what?" Loki demanded.
"You will be confined to the palace during the mating season, and fitted with a chastity belt," Laufey said.
"Father, you can't possibly--" Loki started.
"It is for your own protection," Laufey said, watching his son in concern. "Loki, you are much too young for such things. And as it has become clear that you have ways of leaving the palace, I need to make sure you are protected at all times."
"Please, father, don't do this, I will stay in the palace, I swear it!" Loki pleaded.
Loki had always been able to get his father to give in to him, but in this matter he would not be swayed. He called for a metal-worker to be brought at once and would not let Loki out of his sight until he arrived.
Loki was measured and then locked in his room for the night. He had ways around that, of course, but his father would not see reason and running—unless he did not plan to return—would do him no good.
The gilded chastity belt was placed on him and locked early the next day. The front panel cupped his genitals while a thin but strong gold thong wound around the back and then was locked.
Only Laufey had the key.
His loincloth hid the belt well enough, but it was horribly constricting—rubbing against him with every move. It was crafted so he could still relieve himself, but that was about all he could do.
He had thought it would be a simple manner to magic out of it, but his father, it seemed, was wise to him.
It was warded against magic by the Dwarves.
Under the watchful eyes of his father and brothers, Loki was not able to leave to attempt to find a way around it. He ended up spending the next three mating seasons being locked into the dreaded thing before it began and then not allowed out again until it was over.
On the eve of the fourth mating season, however, he got his hands on a book of magic that would help him to bypass the wards on the belt.
And he was ready to make up for lost time.