foundlingmother

Inspired by Spirk fics where Spock explains the history of T'hy'la and its history is gay and full of warriors accidentally spontaneously bonding.

There’s ancient seiðr in Jotunheim. In all the Nine Realms, really. Ancient customs where two parties spill and share each others blood, and this binds them together in a magical marriage of body and soul.
Asgard and Jotunheim have a tumultuous diplomatic relationship. They’re often on the brink of war with one another. Young, brash Thor’s not so interested in peace. When Loki sneaks into Asgard and relieves them of the Casket, Thor pursues him. He catches up to him using the portals between the Realms, and they end up engaging in combat against one another in one of Jotunheim’s caves. They spill and share blood, and Loki’s spells have attracted lingering seiðr, and suddenly they can’t land blows against one another. Or, they can, sort of. Loki stabs Thor, but the same wound appears on him. When he heals it, it heals on Thor, too.
Queue some really awkward negotiations and Thor talking to his mom about how much this sucks and Loki’s brothers finding it all hysterical.
Thor’s only convinced that he’s really married to Loki, not just stuck with some freaky bond, when he realizes he can’t rise to the occasion with other people.
Loki tries to undo the seiðr linking them, and Thor learns that he’s trying and offers to help. And maybe they start to find they work well together and kind of enjoy the company of each other, but they obviously still need to end this, right? Even if they suddenly find themselves imagining what it would be like to have sex. That’s just the magic… probably. Anyway, they make things worse in the process by enabling an evil sorcerer in accumulating a great deal of power, and Thor and Loki have to work together to protect both Asgard and Jotunheim from them.