The movie ended and we both started doing our own things. She started reading a book she had brought along, and I want back to my room and started to play some video games.
Um....I'm not much into this dating thing, but the fact you went and did your own thing when your were both still technically on a date sounds really odd to me, have things changed that much in recent times that this would be considered normal?
I'd only leave my date to her own devices like that if we had been dating for a while. In fact I wouldn't even be comfortable leaving anyone who I don't know that well to their own devices at my place period. My parents always drilled it into my head that you always keep guests company.
Ofcourse it is possible, that while you were busy playing games, she had a snoop around and found your porn stash or something, but the fact you ignored your date to play computer games sounds like a big no no to me. If you were done with your date why didn't you offer to walk her home or something?