blowjob vs oral sex

blowjob

noun
  • An act of fellatio, or sucking a penis or other phallic object (such as a dildo). Stimulation of somebody's penis or testicles with a person's lips, tongue or mouth with the purpose of giving the receiver sexual pleasure. It may or may not result in orgasm. 

  • Excessive praise. 

oral sex

noun
  • Stimulation of the genitals using the mouth. 

How often have the words blowjob and oral sex occurred in a corpus of books? (source: Google Ngram Viewer )