How or when to know if satisfaction/happiness IS mutually reinforcing OR NOT?

Is this within self or between individuals?  I know I am satisfied & happy when I complete a project & it turned out perfect.  I feel both knowing that my bf feels the same way about me as I do him.  Am I on point or did I completely miss the point?

You can tell if one person isn't too interested.

Happiness is a state of well-being that is characterized by relative permanence, by emotion ranging from mere contentment to deep and intense joy in living, and by a natural desire for it to continue. It thus differs from mere pleasure, which may come about simply through chance contact and stimulation.