It is better to understand that human love, until it is uplifted by high idealism or rooted deep in the soul, both rare possibilities, it invariably leads a trail of disappointment and bitterness. The other thing that keeps a relationship rooted is marriage, especially child or children. Here the couple, though often disappointed, carry on due to social and other obligations. In the absence of a common aspiration and uplifting ideal relationships generally drag along. So remember the good and beautiful moments you both had together and now move on without blame or complaint since human beings and human love is necessarily imperfect.
Affectionately,
Alok Da