Как по Английски будет вода под мостом

phrase

Used to refer to events that are in the past and consequently no longer to be regarded as important.

Примеры использования:

I don't want to talk about that—it's all water under the bridge now

idiom

Something that happened in the past and cannot now be changed

Примеры использования:

Yes, we did have our disagreements, but that’s water under the bridge.