When Loki is sacrificed to the Asgardians - and yes, he sees it as a sacrifice, not a ransom - he expects the king to take his pleasure on the very first night.
He agonizes over it - roils and sickens and trembles - but the king never comes to claim him, not on the first night and not on the second, and by then, the wait has become less terrifying than insulting.
Loki can damned well do his duty.
And so he goes to the king's bedchamber, himself, clad only in a frost-cloak that glitters and clings, and climbs astride the sleeping king.
"Loki," says Thor, when he wakes, daring to sound surprised, and it's hateful that his flesh is still warm, that his lips aren't flecked with blood, blackened with poison. "You - what are you doing?"
"I am your consort," Loki tilts his head. "My king. Or have you forgotten?"
"I… I thought you wouldn't want - "
"Let me be the judge," says Loki, softly, "of what I want." He lets the frost-cloak melt away.
Thor stares at him, at his wet, gleaming skin, and shivers, as Loki lays a hand on his heart, although he cannot know that Loki would dearly love to claw it out. "You're so cold..."
"Yes, I am," Loki says, and smiles. "But you're not." Not yet.