In Chapter 9, why did Alice sleep in the dressing room?

Alice read the little blue book. When she came home, she washed up and put on a pretty silk nightdress. When she got into bed with Barrett, she tried to get him to make love to her. He just pushed her away and called her a prostitute. Then he threw and broke a lamp. Alice picked up the lamp pieces, pulled on a bed jacket, and she went to sleep in the dressing room.