A.N-This is inspired/based on a few different things: the mythological suggestion Freyr and Freyja may have been married/in a relationship, a scene from the anime in which Freyr forbids Freyja from marrying Loki, and a scene in the second manga, vol. 3 (viewed by a sneak peek on Amazon.)
From the very start, they had belonged together. He was hers and she was his.
They shared an existance, a beginning, a life before life in the womb of their mother-aunt. And, so he had been told, when he was born he had not uttered a sound, stubbornly keeping his mouth closed until she, his sister, his twin, his other half, emerged, and then the two had cried together, their voices mingling as one. His sister, when she heard that story, would always laugh and say he was too stupid to know what to do and needed her to show him how to breathe. But he, in his deepest of hearts, had always firmly believed that he had been waiting for her. Already he had decided that, if she was not born, if she did not live and survive, he didn't want to either, so important to him was she.
And so they grew, becoming children, laughing and playing and loving in the land of their birth, Vanaheim, safe in the knowledge that, if they wished to become closer than most siblings, it was all right, because they were Vanir and the Vanir did not mind such unions. Their own parents had such a love, so why couldn't they? As teenagers they expressed their feelings for each other, experimented with their love, becoming closer than they had ever been since they exited the womb.
But then the Great War came, and their lives were shattered. Everyday was waiting, fighting, surviving, praying that it would be over soon — who they were praying too, they did not know, for what power was higher than that of the gods? And then, the end did come, and peace reigned between the Aesir and the Vanir — but at a price. Their father, Njord, was part of the trade, and so was he — given away as captives to ensure the truce. And she, she, his lovely darling sister, bereft at the thought of losing them, volunteered to go after them, to be with him, despite the sorrow of their mother. He never told her, but the day she had called his name and clung to him, crying and begging, was perhaps the best of his life.
They had, foolishly perhaps, believed that they could continue as they were, loving and living together in Asgard as in Vanaheim. But that would not, could not be, for the Aesir were closeminded and frightful gods, attacking anything that was different and strange. So he had to part from his beloved sister, his darling wife, his beautiful Freyja. They were the gods of love and beauty, but their love had been crushed and the beauty of their world dulled. Though they both eventually married and coupled with their spouses (and others), as was their duty as fertility gods, it was never the same.
Eventually, they grew used to the odd restrictions of the Aesir. At least they still saw each other, which would not be the case had she stayed in Vanaheim. But neither was truly happy in Asgard, with their depressed father and awkward friends and hateful spouses (for Gerda had been wooed with threats and so loathed him; and Odd despised both being the rebound and Freyja's numerous affairs. Surely everyone knew her tears of gold were those of joy, not mourning). How he longed for the days of their youth and the land of their birth. Mostly, though, he wished to see a real smile on his sister's face.
And then, his wish was granted. One day Odin came home with a Jotun in tow — but the surprising part was that the Jotun was not dead, nor in chains, but laughing with the Allfather as if they were the best of friends. And indeed, they were more than that; they had mingled their blood and become brothers. This new addition to Asgard was given the title of god of fire and, at his suggestion, mischief and trickery.
"My father's people, the Jotuns, would surely agree with this, for they know the truth of it," the new god, Loki, had said, chuckling. Hesitantly and haltingly, the others joined in. All eyes were on him, but two: Freyr's, for he was watching Freyja watch Loki. And what he saw in her eyes broke his heart, because she watched the Jotun the way she had once watched him, lovingly and adoringly.
How cruelly wishes are granted.
And then, Loki was banished, and Freyja smiled even less. And then she, too, was gone. He begged Odin to go after her, as she had begged before for her precious Loki. Amused, Odin allowed it, on the condition that he would aid Heimdall in his attempt to kill Loki. Wishing so much to find his sister, Freyr had agreed.
It took him forever to find her, and when he did, she was as enraptured with Loki as ever, though he had only ever caused her pain. She wanted to marry him, for Ymir's sake. Had she forgotten her first, her true husband? He had been so naive. Yes, she had loved Loki, and yes, he was married, but — that was in Asgard. They were in the land of the humans now. He'd thought...he'd thought perhaps they could be as in Vanaheim, brother and sister, husband and wife. True, that Mayura girl had caught his attention, and he was head-over-heels for his Japanese Beauty. But Yamato Nadeshiko hadn't been his only love. She hadn't been his first.
For the rest of his life, his heart would belong only to his sister. His twin, his other half, his wife. Freyja to his Freyr; Lady to his Lord.
A.N-Okay, in case you don't know, here's a little explantion for the mythology references: Freyr and Freyja, sometimes considered twins, were of the Vanir race, born to Njord and his unnamed sister-wife. Such unions were not frowned upon in Vanaheim as in Asgard; it has been suggested they, too, had engaged in an incestuous relationship.
However, when Njord, Freyr, and Freyja went to live in Asgard as part of a truce treaty between the two races, their relationship was so taboo they were forced to give it up.
Freyja is portrayed as somewhat of a whore, sleeping with Odin from time to time, and she even won her necklace Brisinggamen by sleeping with the four makers on four consecutive nights. However, she was said to 'weep tears of gold' for her 'lost husband Odd.' (This may have been another name for Odin). Freyr, too, married a giantess, Gerda. He fell desperately in love with her, but she did not want to marry him. Freyr asked his foot-page for advice; the page goes and threatens to curse the giantess if she refuses to marry his master. In the end she concedes.
Now to talk about Loki, he's an interesting character, as I'm sure we all know. He was said to be the son of Laufey; his father was the giant Farbauti. His mother, Laufey, may have been a giantess as well, though some think that she may have been of the Vanir. That's why I have him say 'My father's people, the Jotuns'
Finally, the names: a possible translation of Freyr/Frey is 'Lord', and Freyja may mean 'Lady'
I'm rather proud of this piece. It sort of shows a serious, anguish-y side of Freyr that you might not ever see. If also has a more Norse mythological feel to it.