For those who have been in a relationship for 15 years plus:
Have you still got that special 'spark'? If not: when did it disappear, what did you do about it, did you ever get it back? If you haven't got it back, have you accepted your relationship on different terms, or moved on? Is it unrealistic to expect a spark after many years, especially when a relationship is, for most of the time actually quite harmonious? Do you think your spark disapeared because one or other of you had changed?
Sorry to ask so many questions - in a bit of a pickle at the mo, and need other perspectives please!