"Betray him and I'll kill you."
Insert unnecessary love triangle here. If you ignore Jane Foster, which for me wasn’t really hard because she was a bit flat, you have Thor<Sif<Loki at least in my mind. I think the way that line is delivered, Loki might have had more than a passing fondness for Sif.
Even though I totally ship Sif with Thor it’s not nearly as interesting as Loki and Sif. For me Thor/Sif belong together so I don’t even need to read fic about it because it’d be boring. But give me all the fic about Loki/Sif dancing around each other’s feelings for each other, the fights, the angst, the sneaking around, the awkwardness, just give me all of it. I don’t see their relationship as an epic, forever love but I do love that line and the way it’s delivered because it hints that something may have happened in the past thousand years and I’m content with it staying in the past. No love story for Loki in the films please. :)