It will take the efforts of both partners to find reason for the lost feelings. One partner cannot do this alone.
It will take courage and honesty from one, trust, maturity and understanding from the other.
Sharing these feelings, even if they are not what a partner wants to hear, is vital to the success and longevity of a relationship. Hearing that your partner is having issues in their feelings toward you is not easily accepted, as immediately they are taken as a personal attack or even as a feeling of failure. Fair enough, take a minute, have your pity party, but then, do move onto the issues at hand. Your partner is being very brave and in that bravery, she/he is taking great risk of being misunderstood. In that action alone, respect and an open mind should be given in turn.
It is a time when both partners must take their part in the relationship serious.
It is time for both partners to remember what brought this relationship together in the beginning and work from there.
It is a true reality check, that somewhere something has been forgotten or taken for granted.
It is time to find what has been lost between each other and why.
It is not the time to play badminton with blame or fault, it is not the time to dig up past indiscretions or mistakes.
It is not time for name calling or using hurtful selfishness as a weapon. If partners allow these reactions of destruction to take place, the relationship will then most undoubtedly come to a bitter end.