不知好歹 [- - hǎo dǎi]not to know [distinguish] good from bad; not to appreciate what is good; not to know what's good for oneself; not to know chalk from cheese:
•¶ 你不但不谢他， 还埋怨他， 真不知好歹。 You are really an ungrateful wretch to complain instead of thanking him.