ingenuous vs wet behind the ears

ingenuous

adj
  • Unsophisticated; clumsy or obvious. 

  • Straightforward, candid, open, and frank. 

  • Naive and trusting. 

  • Demonstrating childlike simplicity. 

  • Unable to mask one's feelings. 

wet behind the ears

adj
  • Inexperienced; just beginning; immature (especially in judgment). 

How often have the words ingenuous and wet behind the ears occurred in a corpus of books? (source: Google Ngram Viewer )