Celborn, Galdriel and Elrond

[Kuruharan]

What if, for example, Elrond had met Galadriel on some moonlit stroll through Middle Earth before Galadriel ever married Celeborn, and sired Arwen...

It would be a very good trick!
Even more so because Galadriel and Celeborn had been married for centuries before Elrond was born.

I think what Rosa U. means is that it would not be in keeping with Tolkien's whole ethos.
It's just not the sort of thing that the good guys and gals in his world do.
Not at least without nasssty consequences.