One Hundred Steps There (слэш)

Prompted on Norsekink
Prompt:
Thor and Loki (both are adults) are secret lovers. They've been in relationship for a while, and they really love each other.
One day a delegation from Vanaheim arrives. Their relationship with Asgard hasn't been good lately; while their king is loyal to Odin, there are people in his kingdom that want to be independent from Asgard. Most people know that it won't do much good to Vanaheim, but a group of revolutionists keep spreading their ideas.
They manage to find some more-or-less good decision. But then the old king sees Loki and secretly admires the young, beautiful prince for hours. He can't help but suggest Odin an arranged marriage, saying that the presence of an Asgardian consort in Vanaheim can make things better. He's a widower, already has heirs, so it doesn't matter to him if Loki gives him children. Odin thinks that it makes sense. He announces that Loki is to marry the king of Vanaheim.
Rest of prompt in notes.