All stories, if continued far enough, end in death, and he is no true-story teller who would keep that from you. Especially do all stories of monogamy end in death, and your man who is monogamous while he often lives most happily, dies in the most lonely fashion.
The world is: fun, and familiar, and healthful, and unbelievably refreshing, and lovely. And it is the theater of the spiritual; it is the multiform utterly obedient to a mystery.