boff vs sex up

boff

verb
  • to have sexual intercourse (with someone) 

  • To hit; to strike. 

noun
  • A great success; a hit. 

  • A pupil who works hard; a swot. 

  • A line in a film etc that elicits such a laugh. 

  • A big laugh. 

  • A hit or smack. 

sex up

verb
  • To take part in sexual acts with. 

  • To enhance in terms of fashionable appeal. 

  • To sensationalize. 

  • To make more sexually attractive. 

  • To arouse somebody sexually 

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