When you were talking about girls taking off their clothes for no apparent reason, the first thing that came to my mind was the Prince of Persia, who in Sands of Time did pretty much the same thing. (i.e. over the course of the game he would tear off various parts of his outfit until he was down to his pants, for no reason I could see...)

Another thing about sexuality in video games... There's gratuitous sexuality (e.g. Dead or Alive), and then there's tasteful sexuality (e.g. when Jim Raynor first meets Sarah Kerrigan in Starcraft). Since all humans have some sort of sexuality, it follows that the most realistic video game characters will too.