Author's Note: Based on the idea that Kurogane one day casually tosses out an offer to marry Fai in whatever world they want, according to whatever custom Fai wants. Maybe Fai finds out more about marriage traditions in Nihon and is puzzled at some of the ceremonies. What's important is the meaning, not the form, so Kurogane mentions that a separate ceremony is fine too, if Fai needs something more or different.
If he wants to honor his birthplace and parents with whatever he might remember of Valerian customs, that's fine. And if he wants to pay homage to the world and man who adopted him by having a Celesian ceremony, that's fine too. Or if he's run across a world in their travels with traditions that struck him as particularly beautiful or appropriate, Kurogane is open to new ideas (and oh, how times and people have changed).
Fai, as Fai sometimes does, takes the idea and runs with it. (Some things stay the same.)
And not just runs with it, but puts wings on it and sets it on glittery magical fire while laughing gleefully. If it was just a mania for parties, this would just be new fodder for fights between Mommy and Daddy, but while babbling on excitedly about options Fai actually lets slip a few honesties, accidentally exposes a few hurts. He thinks it will be so much fun and it'll make up for all the birthdays he never got to celebrate. Mokona and Syaoran will be so excited and he loves the idea of binding the two of them together in all these different ways.
Kurogane, as Kurogane often does, pays attention.
And because this is not just Fai being silly but Fai being honest about what he wants, being comfortable enough with his loved ones to share private thoughts, being brave enough to ask for something for himself, caring enough about himself to know that he deserves to be happy too, Kurogane agrees to multiple weddings as they travel without any real argument. Fai blinks a moment, off-balance because he was fully expecting to be told that he was being a frivolous idiot who wasted money like it was air, and then whoops with joy.
Syaoran begins researching wedding traditions in every new world too, not just souls and vessels and the mechanics of reincarnation. Fai and Mokona make a lot of plans and see about one percent of them through. And Kurogane…is still Kurogane.
In a world where couples dress in long flowing layers and mingle wine together by candlelight, Fai and Kurogane are married in their little kitchen one night while Syaoran officiates and Mokona cheers. Kurogane brings home a small bunch of grapes almost every day and leaves them for Fai to eat. Fai is puzzled but pleased and nibbles the sweet spheres straight off the stems as he cooks.
In a world where lovers gather in the center of the village on market days to be showered with flower petals by onlookers and be given bags of grain by the elder, Fai and Kurogane are married in their work clothes and go home early one day to make bread together. As they walk to work and go to market and visit storytellers, Kurogane often picks a single small flower and tucks it behind Fai's right ear. Fai laughs and tries to reciprocate, not understanding in full but knowing in the back of his mind and the center of his chest that there is something behind these small gestures.
In a world where life-long partnerships are formed by paying great prices and exchanging personal tokens, Fai and Kurogane decide with half-rueful laughs that they are already married. They only stay a few days, and Fai does not notice if Kurogane picks up any new habits.
In a world where families tie their children together for the next generation with elaborately embroidered ribbons, Fai spends several nights running on a straw-stuffed bench with a basket full of spools in his lap, watching in fascination as Kurogane takes the design Fai had drawn on paper and replicates it in thread on the slender white ribbon they'd purchased. Emblems for Valeria, Clow, Nihon and another Nihon are cleverly worked into a single floral pattern, and the worlds mingle together repeatedly along the stylized vine. Fai wears the ribbon in his hair after the wedding, and Kurogane catches it in his fingers to bring to his lips at least once a day.
Fai draws Syaoran into conversation with playful casualness one day soon after their ribbon ceremony, knowing the young man can see right through the act but knowing also that he'll respectfully refrain from questions or sly surmises. Fai finds out more about the marriage ceremony they've already gone through, and also about this world's courtship traditions and declarations of love in general. Syaoran, with a casualness not quite as practiced as Fai's, takes it upon himself to mention that Kurogane-san had asked questions too, and by now Fai's not surprised.
They wear green robes and crowns of ivy and hold hands while a beam of sunlight slowly passes from one side of them to the other. Marry me. Kurogane offers Fai fresh water to drink almost every morning, as if he's afraid the mage will wilt in the summer heat. I love you.
They exchange rings and promises of fidelity, respect and affection while wearing their cleanest clothes. Marry me. The ninja brings home a fresh flower every few days and leaves it for his husband in the vase on the kitchen table. I love you.
They chop wood together and spend the night in each other's arms before the hearth, taking turns keeping the fire fed until dawn breaks the next day. Marry me. Kurogane saves the first bite of his breakfast for Fai to taste. I love you.
It's not until they get to Nihon that they finally circle back to part of the conversation that had started it all, and speak of the customs Kurogane grew up with, and discuss the traditions Fai remembers. The night before the three-day wedding celebration that Tomoyo has deemed to be absolutely necessary to honor the foreign noble her ninja has brought home, Fai is pale and trembling and breathless, a small blue stone in his palm.
"I know I'm asking a lot of you. It's beyond just you and me, what we are to each other, and I'll understand if you won't. If you can't. But it's what I want."
Marry me.
Kurogane doesn't hesitate, exactly, but he does give the question the time it deserves. He considers all the ramifications of the gift (the curse, the commitment). An immediate acceptance would be a declaration of affection, perhaps, but also a dismissal of the weight, the gravity, the enormity of what Fai has offered, and what Fai has asked. Fai deserves the best of him, whether it's yes or no.
He takes the crystal, slow but sure. Presses it against his skin, feels it sink into his bones, takes in a steadying breath against the wild rush of magic he can feel roaring through his veins like a floodwater.
I love you.