the bruce/hulk relationship is slightly symbiotic, they need one another. As an audience we need to relate to both of them
Bruce never looked at the hulk as a curse but rather as a subconcious means of dealing with what problems he had with his father, or trying to get from A to B.
saying this, the hulk's used bruce's intellect to save the pilot, bite off a war head safely on a missle, revisit his old base home, remember how to get to seattle, destroy his old lab in a sucessful manner, and ultimately defeat his father.
while it's also arguable that the hulk has conciously helped to save bruce's life before if you take the falling scene as a representation of the hulk not allowing a tranformation back to bruce to occur because the 'PUNY HUMAN' wouldn't survive the encounter.
i think the reason this hasn't yet happened is really because the hulk hasn't done anything wrong.
The hulk on screen isn't a mindless one, it's grounded and moral. IF perhaps we saw it going on more rampages and accidentally causing people pain, especially ones close to bruce (a single scene with betty getting accidentally hurt would do this), then the relationship would indeed need to change.
But to be fair at this moment, the dialogue points to bruce being favourable of this opening within him, the 'I like it' line points to the underlying fact that we all wish to be truelly free and the hulk expresses that desire in him especially since he was surpressed for a large part of his life.
if you see the peace in the hulk's face during his jumping scenes, you can't hint all parties are having a decent time. I mean seriously, would you wanna hate/get rid of that?
