cold fish vs poker face

cold fish

noun
  • A heartless individual; a person lacking empathy and emotion. 

  • A sexual partner who, during sex, lacks vigor or emotional reciprocity. 

poker face

noun
  • Any similar expression used to prevent giving away one's motives, feelings, or situation. 

  • An impassive facial expression cultivated to prevent other players from determining whether one's actions in the game are the result of a quality hand, or of bluffing. 

How often have the words cold fish and poker face occurred in a corpus of books? (source: Google Ngram Viewer )