I believe this is a common struggle with the people of the western civilization. Our divorce rates are high as well as depression and anxiety. We give ourselves freedoms and less restrictions which in turn make us think that we have a deeper obligation in remaining authentic to ourselves. Thus if we grow out of a relationship we engaged in when we were younger, it would not be authentic to stay true to a promise we no longer feel.
C.S. Lewis picks at the minds of those who support absolute right to happiness. Where are the boundaries to achieving this happiness? Happiness, also meaning 'sexual happiness' within the essay.
I'm not entirely sure if I agree with C.S. Lewis catering to our sexual desires. I do believe that he is right in saying that we mustn't place our desire so high to the point where we are stepping over other moral boundaries. Stealing is stealing, no matter what you steal and for what reason. But giving in to sexual impulses is not harmful, it's how we do this that can prove a detriment.
Sleeping with many different people is not how one goes about being sexual in a positive manner. Rather, speaking and opening up to others and connecting on a social level can prove to be just as sexual if not more so. One can be completely celibate yet still be more sexual then someone who sleeps with a few people a week.
C.S. Lewis does bring up a good point in which some actions that we do see as immoral become glorified when the cause is sex. But it is not because we are so ruthless, but because of what sex promises in the moment. We are continually lured into it's promise of happiness and continually finding it to be illusory.
But the point is that we cannot see our right to happiness as unlimited. It will only bring us to step over more and more boundaries to achieve such happiness which in the end help us dissolve altogether.