出尔反尔 出爾反爾

    chūěrfǎněr

    1. Idiomold: to reap the consequences of one's words (idiom, from Mencius); modern: to go back on one's word; to blow hot and cold; to contradict oneself; inconsistent

    他答应帮忙又反悔,真是出尔反尔。Tā dāying bāngmáng yòu fǎnhuǐ, zhēnshi chū'ěrfǎn'ěr.He promised to help and then went back on his word; he is truly inconsistent.