get over on vs slip it to

get over on

verb
  • To have sex with. 

  • To take advantage of. 

slip it to

verb
  • To sexually penetrate 

  • To smuggle (something) to someone; to surreptitiously pass (something) to someone. 

How often have the words get over on and slip it to occurred in a corpus of books? (source: Google Ngram Viewer )