Whenever life spans are a problem I do this as a coping mechanism:
Imagine that they went to some old wise being or book and found a way for the human to live as long as his hubby like by drinking their blood or a blood pact. One is unable to die unless the one with longer lifespan dies of old age. No it cannot be any other death, has to be old age. If the one with longer life dies from other reasons, the human will die if he is older than normal human life span but if not then he will live but can be killed and die.
Whenever life spans are a problem I do this as a coping mechanism:
Imagine that they went to some old wise being or book and found a way for the human to live as long as his hubby like by drinking their blood or a blood pact. One is unable to die unless the one with longer lifespan dies of old age. No it cannot be any other death, has to be old age. If the one with longer life dies from other reasons, the human will die if he is older than normal human life span but if not then he will live but can be killed and die.