Spirituality and Sex are not two different subjects, but one in philosophical point of view. Actually the nature itself is a combination of male and female energy and in Hindu legends it is known as Siva and Sakthi. The power of the nature is one which is classified as two with its manifestation process. The union of a male and female with their full willingness is a sacred kriya as per Indian culture. That is why in India marriages are arranged by the parents supported by devotional services. Moreover as per Indian philosophy a family man can execute devotional service for the sake of Self realization. But with a condition that he should maintain his chastity as the highest virtue as he may maintain relation with his wife only. He can have Sexual relation with his wife only for the sake of future generation and it should not be misused for sensual pleasures. This will enable him to reach the highest perfection of life, Realization. Bhakti yoga, pure devotional service to the Lord, is the highest and most expedient means for attaining pure love for the Lord the Almighty, which is the highest end of spiritual existence.Those who follow this supreme path develop divine qualities. In the universal language of mind, sex represents harmony. Sex represents the progressive harmony between the conscious and subconscious mind. This is the dream language which can also be applied to scriptures.Although sex is physical, it is an emotional connection of Souls and spiritual act.Every simple act of sexual intercourse is an act of worship. We, the human beings are the prototype of this great Universe which is representing us as Man and Woman. As per Vedanta philosophy, Man is the expression of God and God is the reality of man. Real man and God are inseparable.
The other side of the story is different.There are various yoga and meditation techniques to transform sexual energy into kundalini or spiritual energy by oneself. However, its ultimate purpose is to facilitate spiritual growth by developing our chakra system and higher energy bodies. Pure romantic relations will definitely help to awake the Kundalini, the spiritual energy. Chronic diseases like cancer and heart diseases can benefit greatly by a close loving relationship. Necessary hormones will be produced during this time which can heal the patient to great extent.