Пошел от списка "японских пословиц" и вот что нашлось в
буржуйнете:
覆水盆に帰らず。
* Fukusui bon ni kaerazu.
* Literally: Spilt water will not return to the tray.
* Meaning: It's no use crying over spilt milk. / A separated couple can never go back to as it was.
* Background: Original meaning comes from an old Chinese story of a couple, but the proverb is often used in a more general sense today.
Видимо это близко в контексте, который мне нужен...?