That's the silly thing. They still "love" us, but believe that they are not "in love" with us.
Thus the ILYBINILWY speech we all heard as our hearts were stabbed with a 20 or 30 year long knife.
Here's the thing: That "in love" feeling they are searching for (sometimes called Limerence) typically lasts 6 to 24 months.
Because I'm brave, (or stupid) I once told W "so you're going to find someone new, and it'll be real hot for a year or two, and then turn cool. What then?
Several months later she admitted: "I know the hotness of a new relationship won't last"
...and she's still here, sans OM.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl