The pain, mild though it is, is an exquisite and much-loved counterpoint, a burn in the shape of his fingers on the back of his neck. Probably fortunate that she doesn't grow her nails out long like less-warlike court ladies. That's impractical with a sword or a dagger.

"Mark me," he whispers against the hinge of her jaw, kisses her there. "I'm yours."

Lest there be any doubt, in his mind or hers. Thor can draw his own conclusions. Part of Loki would enjoy watching him draw his own conclusions, but in the end it doesn't matter; what's between Loki and Sif is between Loki and Sif. His brother does not need to be a third party to their relationship. Sif isn't some pretty prize he's successfully won from Thor, though their rivalry tempts him to think that way. She's a wildfire, belonging to no one unless she gives of herself, and she's chosen to burn in Jotunheim.

But oh, yes, he wants to feel her come, more than anything, and when she tugs him by the hair and looks into his eyes there's a feral light there. His left arm tightens, holding her tight, his body pressing her against the wall, and his right hand slips between them. The pad of his thumb presses and rocks against her clit, firm but not rough, and his next thrust is less wild and more precise, every angle calculated to hit as many sensitive spots as possible.

He holds her gaze, bright and hungry and arrogant, determined to watch her fall apart before he takes his own pleasure.