Thor remembered the first time Loki was pregnant.
Or maybe it wasn't the first time. Likely it wasn't the first time. But it was the first time he knew about, the first time he was privileged to watch.
They had been at odds at the time. Over what, he couldn't remember. It had probably been important, then. He had chased the trickster halfway to the end of the earth, which was not nearly so far as he usually had to chase him, and found him flushed and panting beside an olive tree.
Tying their hands together so that Loki would not escape, Thor had prepared to lead them back to Asgard.
Halfway there, as they were camped beside a fast-flowing river, Loki had groaned, fallen to his knees and begun to claw at his stomach. Suspicious, Thor had asked if his brother had contracted body lice on their journey.
Loki had screamed, in a voice that echoed off the heavens, "GET ME A KNIFE, YOU GORMLESS HALFWIT!"
Against his better judgement, Thor had proffered the knife with which he had skinned the rabbits they had eaten that evening. Amazed, he had watched as Loki plunged the knife deep into his own gut, from which then seeped not blood, but light, white light. The knife had been pulled from one side of his brother's abdomen to the other, a grisly smile of a wound, and then Loki had reached in, deep in, and pulled from the mess of white light and organs something small and wriggling.
He had handed it to Thor, who had hesitantly taken it, and then collapsed backwards, gasping in pain as he pulled out the blade.
It was a baby bird. No feathers, the barest hint of a beak. When Thor had used his cape to clean it, it had snapped at his fingers, and then burst into flame.
"Brother," Thor had asked, frowning at the blazing fledging cupped in his hand, "did the world really need another one?"
"They were extinct," Loki had rasped, busy sewing himself back up.
"Aye. With good reason."
"I wanted one."
"How many did the last phoenix slay, brother? How many fields did it set ablaze before we brought it down?"
"There will always be fields. Give it here."
Thor had handed the baby bird to its parent, whose body was slowly coming together again, and sat in silence as Loki plucked off one of his fingernails with his teeth, and let the phoenix suckle on the bleeding tip of his finger.
In the centuries that follow, the bird became part of a menagerie.
"I like having children," Loki had said, matter-of-factly, when Thor had thrown up his hands and confronted him on the matter of Sleipnir. "There's nothing wrong with that."
"You're a man," Thor had growled. He knew his brother was a wild one, knew he had the makings of a fiend, but somehow he couldn't align the image of the quiet, composed, soft-spoken man before him with the eight-legged horror cantering about in the courtyard. The phoenix, at least, had been small.
Loki's eyes had flickered up to him, flickered away, and he had offered nothing in his defence but the tiniest of shrugs.
When the truth came out, it explained so many things.
"There is no such thing as a frost giant woman, just as there is no such thing as a frost giant man. They do not recognise either sex or gender as we do," said Father, whose knowledge of the subject seemed altogether too intimate for Thor's liking. "Their language has no pronoun equivalent to 'he.' And biologically speaking, your brother isn't a man anymore than you are a potplant."
"And you didn't think it was worth telling me this," Thor said, in a hollow voice. There was no anger. There was no room for anger.
"I don't tell you lots of things, Thor," Father said. He sounded tired.
"More," Thor said, "what more is there?"
Now that he had the truth in his hands, he was cursing himself for never having sought it before. It had, in all honesty, never occurred to him that Odin would keep such secrets from them.
In the aftermath of the hideous fruit those secrets had borne, Thor was beginning to realise that the least ruinously conniving member of their family was, in fact, himself. And in light of the cosmic war his duplicitous mission to Jotunheim had very nearly started, that fact became deeply depressing.
Odin sighed, and returned to the list of biological traits that distinguished Jotunn from Aesir. Thor concentrated, his brow furrowing. If his little brother truly was one of those... people, not things, vicious, ugly people but people... then the thunder god would make it his duty to learn everything there was to learn about them.
Several summers after the truth came out, and Thor had accumulated a wealth of knowledge regarding Asgard's ancient enemies. It had been enlightening, to a man who had assumed that music and astronomy were exclusively Asgardian occupations. Some of it was also horrifying, alien, and had done little to dissipate the tension that remained between Odin's sons.
All Asgard first knew something was amiss when Loki appeared out of thin air in front of Thor in the courtyard on a clear midsummer's day, smiled politely at the assembled gods and goddesses and then broke Thor's nose with one swing of an iron kettle he had concealed behind his back.
Before saying in a loud, clear voice, "I refuse to accept the blame for this," and disappearing in a flash of green light.
"How peculiar," said Thor to the world in general, as Balder rushed to his side and Idunn called for the healer. "My brother is usually so willing and eager to accept responsibility for his actions. A strange day it is, when Loki refuses to accept blame."
The sarcasm dripped from his voice even as the blood dripped off his chin.
Two days later, there were an inordinate number of wildfires blazing across the length and breadth of Asgard's forests.
Loki stood at the foot of a new one, having spent the better part of an hour fanning it, and seethed.
He hated him. Hatred sung in his veins, throbbed in his temples. Hate spread warmly down his torso to nourish his…
He hated him.
He left the fire and retreated to the dark and mouldy corners of the world, where he sat and snarled to himself.
Hate, chanted the sickness in his belly and the pain in his ankles. Hate. Hate. Hate.
Lightning danced across the sky. Thor was looking for him.
Loki folded his arms, and curled up on his side. He did not feel like being found just yet.
Once his nose was bandaged, Thor did not tarry.
He searched four hundred caves before he found the one his brother was hiding in.
When he demanded an explanation, he received an unsettling laugh, and then an unsettling diagram, drawn in the dirt with a stick. It took him a moment to work out what it was depicting, and when he did, he shot backwards as though the thing had launched itself from the dust and bitten him.
"You lie," he said, reflexively. At this, Loki turned himself into a squirrel, and went and hid up the tallest tree he could find. After spending a day finding him and another persuading him to come down, Thor skinned two rabbits and cooked them over a fire as a peace offering.
"I don't understand," Thor said, carefully, as he handed his brother the choice portion of meat. "All else aside, we have never lain together."
"Yes," said Loki, who, apart from the initial kettle-to-the-face, was being troublingly calm about the whole thing. "You'd think that would make a difference, wouldn't you?"