>>2260646>She literally gets her 'best friend' (who she never passes up the opportunity to abuse and humiliate for fun) drunk so her beta orbiter can fuck her on camera.More like she's a teenager who's passive-aggressively lashing out at a perceived love rival.
The entire point of the books and anime is that Haruhi is growing as a person. After warming up to the people in her circle of friends - remember, she never cared for other people but was instead searching for the supernatural and took quite a while to mellow out and realize that her friends are better than finding magic or aliens or whatever - she continues in her egoistic behavior until she finds the breaking point (Kyon literally wanting to punch her) and realizes that she's gone too far.
From then on she becomes a very balanced person.
Basically, the same thing that every teenager ever experiences thanks to certain instincts.
In fact, the entire story is about a bunch of people growing - Yuki becomes more human and starts valuing her existence, Kyon stops being apathetic and starts enjoying himself, Koizumi becomes loyal to the SOS-Dan, Haruhi grows up and basically becomes the team mom and Mikuru... Well, Mikuru is actually the wild card, because her situation (being employed by her future self) deprives her of free will. She literally cannot become as loyal to the group as everyone else is.
