what phrases to express this feeling “the serendipity is over”？

Question

There is a beautiful phrase in Chinese “缘尽于此”. My attempt to translate it and express this feeling is “That predestined realtionship ends here” or " “the serendipity has run its course” or " “the serendipity has played itself out”.

Let me try to describe this feeling:

I met someone by serendipity. It was destiny that brought us together. And this force continued to guide us, so we had chance to experience so many things together, and maintain a good relationship for a time. Then the relationship ran its course. Now that binding force was gone, fate has decided that at this point we shall part, and never see each other again. The serendipity and luck in terms of that realtionship have played themselves out and there is nothing left now. It has ended.

Answer 1

There are a few possible phrases I can think of, though none are perhaps quite right.

The spark is gone. The passion has been used up, there is less intensity in the relationship.

That's water under the bridge or There's no use crying over spilled milk. What has happened, happened; you can't change the past, so move on with the situation from here and try to fix what you have instead of dwelling on how you might have prevented it.

You can't step in the same river twice. Things change; people change; every interaction you have is a new interaction because nothing stays the same. ("The same river" here refers to the individual water molecules rushing past; the molecules that were there yesterday have been replaced by different ones today.)

Que sera, sera. A pseudo-Spanish phrase popularized by a song of the same name that is a word-for-word translation of the English phrase "whatever will be, will be" (English speakers use the Spanish phrase as or more often than the original English phrase). A fatalistic but accepting view of the future; not quite a "happy-go-lucky" outlook on life but nearly so. This doesn't have quite the beauty of your original phrase but I think it might be the closest to the underlying feeling.

In the end you might just say "That serendipity is gone." This is slightly stretching the definition of serendipity but the intent is clear.