confess vs open up

confess

verb
  • To disclose or reveal. 

  • To hear or receive such a confession of sins from. 

  • To acknowledge faith in; to profess belief in. 

  • To unburden (oneself) of sins to God or a priest, in order to receive absolution. 

  • To admit to the truth, particularly in the context of sins or crimes committed. 

open up

verb
  • To reveal oneself; to share personal information about oneself; to become communicative. 

  • Synonym of cheat out (“to face or turn toward the audience more than would be natural”) 

  • To begin running, driving, travelling, etc., at maximum speed. 

  • To commence firing weapons. 

  • To rain. 

  • To open. 

  • To widen. 

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