Thank you for your perspective, hvert.

In positing, I actually was hoping for responses discussing the experience(s) of persons who may have initiated chemistry/passion/what-have-you in a relationship that it did not start with or where such feeling may have developed over a long term, naturally or otherwise. Conversely, I was also interested in experience with failed relationships that ended because this component was missing.

It seems to me like a relationship without romantic compatibility is feasible but it resembles more of a friendship, which I am less comfortable with by the day. On the other hand, this relationship style appears to suit my partner. In the end I will have to decide to either work on this with the possibility of never developing the relationship I hope for or leave-- and as you picked up on, my current feelings are pushing me toward the latter.