Sex relieves tension while love causes it
The difference between sex and love is that sex relieves tension and love causes it.
Your example
I don't know the question, but sex is definitely the answer.
My love keeps growing more passionate and egoistic, while his is waning and waning, and that's why we're drifting apart."
She went on musing.
"And there's no help for it. He is everything for me, and I want him more and more to give himself up to me entirely. And he wants more and more to get away from me. We walked to meet each other up to the time of our love, and then we have been irresistibly drifting in different directions. And there's no altering that."
A profile, a look, a voice, can capture a heart in no time at all.
I'm selfish, impatient and a little insecure. I make mistakes, I am out of control and at times hard to handle. But if you can't handle me at my worst, then you sure as hell don't deserve me at my best.
However much you have been wanting and hoping and dreaming of meeting the person of your dreams, it is only when you meet them that you will start missing them. It seems that the presence of an object is required to make its absence felt (or to make the absence of something felt). A kind of longing may have preceded their arrival, but you have to meet in order to feel the full force of your frustration in their absence.