As most people know economics can encompass almost anything and everything. This does not exclude dating. Just like everything else the people in a relationship want the marginal benefit to exceed the marginal cost. So in other words they want there to be more good days than bad in the relationship. You must draw an economic profit of zero just like you do in the normal industry.
A business or person will draw an economic profit of zero because that means that they are doing exactly what is right. That if they are performing in the way that will make them the most money. This is the same in relationships. You must find the person in which you enjoy the most. This falls in the category of the person who you can love no matter what and things like that.
To say that love is an emotion and nothing else is false. In fact, it will always be an economic calculation of feelings. You have X amount of feelings for someone and you want to believe that those feelings are better than anyone else.
Of course, the interest part is are there monopolies? So if you date someone and they restrain from giving affection is that them exploiting the market? Sure, there is a threat of divorce just like there is a threat of revolution but it is very rare. So in relationships how much freedom do you have to disown the slavery you have encountered?
These are just interesting things to think about with no resolved conclusion.