How we cite our quotes: All quotations are from Thor.
Quote #7
LOKI: I never wanted the throne, I only ever wanted to be your equal!
From first frame to last, Loki is consumed by jealousy. Not just jealousy that Thor is the first-born, but that he's going to be the heir of Asgard…something Loki thinks he's terrifyingly unqualified for. And yet Thor's still the apple of Odin's eye, something Loki desperately wants and can never have. It's enough to give you a case of the Resentful Glares, that's for sure.
Quote #8
THOR: Why have you done this?
LOKI: To prove to Father that I am a worthy son! When he wakes, I will have saved his life, I will have destroyed that race of monsters, and I will be true heir to the throne!
Seen by the cold light of day, this is actually really sad. Loki feels so absolutely inadequate that he has to commit genocide in order to prove that he's worth dad's attention. We'd hate to think what would happen if he ever got cut from the football team…
Quote #9
THOR: Loki, this is madness!
LOKI: Is it madness? Is it? Is it? I don't know what happened on Earth to make you so soft! Don't tell me it was that woman? Oh, it was. Well maybe, when we're done here, I'll pay her a visit myself!
Obviously, Loki's not jealous of Jane. But he is jealous of Thor's favored status, and with the delicate stuff set aside, he's willing to go for the obvious target to get a rise out of his brother. (Though that might not be wise: have you seen Thor when he's mad?)