翻悔

yī jīng dā ying jiù bù yào fān huǐ

一经答应，就不要翻悔。

Once you've given your word, don't try to back out.

zhè jiàn shì yuán shì tā qīn kǒu dā ying de xiàn zài què fān huǐ bù rèn zhàng le

这件事原是他亲口答应的，现在却翻悔不认账了。

He was the one who made the promise in the first place and now he's trying to back out.

tā yǔ wǒ men qià tán chéng jiāo hòu yòu fān huǐ le

他与我们洽谈成交后又翻悔了。

He welshed on the bargain she made with us.

tóng yì le yòu fān huǐ

同意了又翻悔

renege on one's agreement

tā fān huǐ le

他翻悔了。

He backed out.