on thin ice vs touchy

on thin ice

prep
  • In a dangerous, hazardous, or delicate situation; at risk. 

adv
  • dangerously, hazardously, delicately 

touchy

adj
  • Extremely sensitive or volatile; easily disturbed to the point of becoming unstable; requiring caution or tactfulness. 

  • Easily offended, oversensitive. 

  • Inclined to engage in physical touch. 

How often have the words on thin ice and touchy occurred in a corpus of books? (source: Google Ngram Viewer )