From Longman Dictionary of Contemporary Englishblow hot and coldblow hot and coldBritish English informalCHANGE YOUR MIND to keep changing your attitude towards someone or something → blow
Examples from the Corpus
blow hot and cold• I can't tell what he wants - he keeps blowing hot and cold.• Some of these young officers blow hot and cold.• In our dealings with the police we have found that they can blow hot and cold. Sometimes they are keen to have media help in solving a crime, other times they are more reluctant. 