Ex-b said that and said that he didn't feel "sparks". Duh! How many sparks do you feel after 3 years? I mean, I still felt them - but not on a constant basis.
By the time you've known someone a while, sparks can take a lot of work. You know each others good and bad side.
What ex-b and I had was plenty enough for a relationship. Attraction on both sides. We talk easily. We have lots in common. He did feel smothered, though he didn't tell me (I can see how, but I certainly didn't need to do all that I did). So he missed "sparks".
I figure at some point that he'll realize he'll never have continual sparks with anyone else. I was his first long-term relationship (his longest one otherwise was like 4 months).
Supposedly he started feeling less sparks at the 2 year mark (suprise, surprise - that is about the time that relationship books say it will happen). Of course, he never said anything - he acted like everything was fine. We got cell phones together, I helped him a little financially in buying a vehicle, we did things together, etc.
Anyway - I think ILYBINILWY means they are lacking in sparks, losing the luster, it's a bit less shiny. And at that point, they generally aren't wanting to work on the R any longer.
