Did he ever get her name?

Early on in the movie when he steals the guest book with names of the people who attended the charity event and he was trying to figure out what her name was. I was wondering after he eventually met back up with her, did he ever ask for her name?

When they were together what did he call her? Why exactly did she never mention her name to him? She was basically leading him on the whole time but never really introduce herself. I found it bizarre.