And he thinks that this prostitute is the woman from the story/game. Also in the beginning all the guys watch this couple have sex in the rooftop of another building.
He also makes out with his best friend by accident after the guys pull him out of a pool. Also catches him about to masturbate when he breaks into his house for help, and the friend ends up calling the cops on him, who later chse him into either the subway or sewer.
And later there's a guy who the kid meets in the subway/sewer and he has a nasty toothbrush and he eats a rat.
And the cops chase him later until there's like a concert or something and he wants the prostitute to go with him or something but she won't because she thinks he's crazy.
Might be some kind of Spanish movie, but I can't remember correctly.