One of the things that we must come to realise is that Nature, (and I use that word to mean "God's system") in all areas of life; plant, animal and human is highly geared for reproduction. It almost seems to have a fear of extinction, hence it yields prolifically, far in excess of its needs. In one act of human copulation there is enough reproductive material from the male to provide for millions of conceptions. Also, to match the material is the instinct. If one was to delineate the strengths of the human instincts according to priority, I suppose self-preservation would come first. As Satan said "All that a man hath will he give for his life" (Job.2:4). Second would come hunger, and sex a close third; and you will notice that all three have a bearing on survival one way or another.
We must also accept the fact that sex has a fascination. It has been very much a part of the British temperament to pretend a disinterest in the whole subject, as though it did not really exist, but we know that's not true, and the media know it's not true. The film with a strong sexual element is big box office. The newspapers that purvey regular moral scandals are assured of a high circulation. Even advertisements with sexual innuendo will most likely increase sales.
Seeing then that there is a powerful dynamism in our sexuality, it must be handled with utmost responsibility, and where it is not so handled it can bring about most unhappy and sometimes disastrous results.