definetly envy

i would have picked envy but jacob isnt jealous by nature, edward always pisses him off when he sees that jacob has a shot at catching bella's eye with something he doesnt hav e.g lyk jacobs HOT abs (as seen from clip by the car) And i only chose this answer coz it has a pic from my fav scene and it kinda makes sense.

Well, just like @taylena2 said, Jacob isn't jealous by nature.
I mean, he's jealous on Edward because of Bella but we all are jealous when we see our crush with someone else.
His excessive desires are that Bella stays human and that he isn't werewolf (by some point of the books).

Of course Envy...