A love affair is like a short story--it has a beginning, a middle, and an end. The beginning was easy, the middle might drag, invaded by commonplace, but the end, instead of being decisive and well knit with that element of revelatory surprise as a well-written story should be, it usually dissipated in a succession of messy and humiliating anticlimaxes.
Humans know when it's not a good story. Unless you do this for a living, you may not know exactly why you don't like a story, but you can't fool an audience ever. They know when you have it and they know when you don't.