Forgive me for not reading all the responses so far—I've only got a few minutes to post. I DO intend to read up, later, as I'm always up for new ways of looking at things.
For me... in my relationship with my mother and father, my love for my parents, for my mother... who died 6 years ago... exists on a different plane, if you will, than my other relationships. Same for my romantic partners. There is no room for competition between the two. They exist on different levels. Apples and oranges... in a way. They can't compete.