Name of book about 2 friends who love each other but time is never right for them to date until later in life?

Two friends who love each other since youth, but are never available at the same time. I think they both get married and divorced and don't become available until later in life. They finally try for a relationship, but something happens to prevent it once again. I read the back of this fiction book and can't remember the title. There might be a detail or two that I mixed up but that's basically the gist of the story. Does anyone know?