Rhett and scarlett have a relationship characterized by a lifetime of marriage characterized by little physical desire and no sharing of thoughts or feelings. this relationship is best described as one of strong:

This relationship is best described as one of strong "commitment".

Explanation:

Whenever you are in a relationship, you must have a commitment, sometimes commitment is strong sometimes it is not. But in marriage or partnership, it is not just about thoughts or feelings, its about commitment and you always have strong commitment in this relationship. we can define commitment as to dedicate yourself to something or for someone.