From Longman Dictionary of Contemporary Englishsomething doesn’t bear thinking aboutsomething doesn’t bear thinking aboutUNPLEASANTused to say that something is so upsetting or shocking that you prefer not to think about it The long-term consequences of a nuclear leak don’t bear thinking about. → bear
Examples from the Corpus
something doesn’t bear thinking about• The reaction I'll get when my parents find out doesn't even bear thinking about. 