Deliberate connection or Duty to love?

When Aristotle penned the well-known quote about excellence, how could this apply to relationships?

Excellence is never an accident. It is always the result of high intention, sincere effort, and intelligent execution; it represents the wise choice of many alternatives - choice, not chance, determines your destiny.
— Aristotle

One of my favorite foundational elements in Aristotle's work is how the application and interpretation can very distinctly between disciplines, individuals, and context. 

When considering how choice has a determinate value in the love relationship, we can interpret how deliberate acts of connection can replace a perceived "duty" to perhaps experience a chance of love. 

Some couples stay together for the benefit of the children, others may remain in a relationship because of convenience, and yet others may find that the pragmatic forces of money and insurance are the glue that hold their relationship together. 

On the other hand, some couples find that intercourse is a relational obligation that must be met while others use it as a means of transaction that happens to take place in marriage. Other couples may use physical intimacy or doing tasks for each other as a source of currency that passes from one partner to the other and vise-versa. 

How can a couple move from this sense of "duty" to experience love by chance and instead embrace the choice of deliberate connection?

Aristotle equated mental/emotional/spiritual shift to the word EXCELLENCE. Many partners contact a couple's therapist wanting to improve their relationship. What if this one mental shift [from viewing love as a chance transaction and moving it to understanding it to be a deliberate choice] could change your relationship from merely existing to excellent