We Were Liars question

It was about a girl named farrah who has a brother, her brother had a best friend who i don't remember the name, but i remember one scene where farrah, her brother and her brother's best friend are watching a movie and farrah put her leg against her brother's best friend, she always had a crush on him!! There's also a scene were he and her brother mentioned a poster of farrah fawcett!! He also pick her up at some place but i can't remember... Please help me find that book!!