Spilt water is difficult to retrieve
Describes situations where the outcome can't be reversed or changed. Often used in reference to divorce.
Negative
花瓶打碎了就算了，覆水难收，我们可以再买个新的 | Huāpíng dǎ suì le jiù suàn le, fùshuǐnánshōu, wǒmen kěyǐ zài mǎi gè xīn de
You've broken the vase now! Don't cry over split milk. We will buy a new one
[Source]
虽说覆水难收，难道他们俩的婚姻真的没有挽回的餘地了吗? | Suīshuō fùshuǐnánshōu, nándào tāmen liǎ de hūnyīn zhēn de méiyǒu wǎnhuí de yúdì le ma?
Even though they say it's over, is there really no chance their marriage can be saved?
[Source]
To cry over spilt milk
What's done is done
None
In some versions of this story, the husband is 姜子牙 (Jiāng Zǐyá), a legendary advisor who lived around 1100 BC
On the surface, this chengyu is very similar to 破镜重圆. However, this chengyu means that a couple cannot get back together, while 破镜重圆 means that a couple can get back together
《后汉书》(Hòu Hàn Shū, "History of the Eastern Han") by 范晔 (Fàn Yè)
In the Western Hàn Dynasty (西汉, 206 BC - 8 AD), there lived a scholar named 朱买臣 (Zhū Mǎi Chén). 朱买臣 was an honest and sincere man, but his scholarly devotion left him deeply impoverished, so much so that he sometimes had to resort to chopping wood to make ends meet. 朱买臣's wife, 崔氏 (Cuī Shì), soon grew tired of this lifestyle, and she had a matchmaker set her up with a well-off carpenter. The moment 朱买臣 walked in from chopping wood one day, she demanded a divorce. He pleaded with her to wait until his scholarly talents were recognized, but she refused so vehemently that he had no choice but to let her go.
Just a few years later, 朱买臣's luck finally changed for the better: a court official who was from the same town as 朱买臣 recommended him for a position, and the Hàn emperor promptly appointed him governor of a province. When 崔氏 found out, she grew immensely distressed, since she knew that the life of a governor's wife was far better than that of a mere carpenter's wife. She soon decided that she needed to beg for her ex-husband to take her back, and she headed out on foot to track him down.
After much searching, she found 朱买臣 sitting astride a tall horse with servants all around him. With disheveled hair, a dirt-smeared face, and bare feat, she piteously entreated him to forgive her and take her back. 朱买臣 responded simply by asking an attendant to bring over a pot of water and pour it on the ground in front of his horse. He then told 崔氏 that if she could return the spilled water to its pot, he would accept her back into his house. Acknowledging the impossibility of this feat, she wept bitterly.