Brothers for Life (слэш)

Prompt Soulmate AU: every realm has soulmates, but no realm's soulmates work the same. Humans can see the red string of fate, Vanir see the world in black and white until they meet their soulmate, dwarves, have tattoos of identical soulmarks. Aesir have the name of their soulmate written on their wrist. Loki has both his wrists filled with names. One he doesn't recognize, the other is Thor. He never admits it to anyone, not even Thor, but he knows, heard enough in the downtown, about polyamorous soulmate bonds. But he also looked at Thor's wrists. Thor never has sleeves on, and he only has one name, not Loki's. Loki always thought Thor was his soulmate, unrequited love, and wore long sleeves and his pain inside. He only learned later that Jotnar also have their soulmate's name on one wrist as a soulmark... And their enemy's name on the other wrist.