No error can be more perilous than to accept the immixture of the sexual desire and some kind of subtle satisfaction of it and look on this as a part of the sadhana. It would be the most effective way to head straight towards spiritual downfall and throw into the atmosphere forces that would block the supramental descent, bringing instead the descent of adverse vital powers to disseminate disturbance and disaster....
          It is an error too to imagine that, although the physical sexual action is to be abandoned, yet some inward reproduction of it is part of the transformation of the sex-centre. The action of the animal sex-energy in Nature is a device for a particular purpose in the economy of the material creation in the Ignorance. But the vital excitement that accompanies it makes the most favourable opportunity and vibration in the atmosphere for the inrush of those very vital forces and beings whose whole business is to prevent the descent of the supramental Light. The pleasure attached to it is a degradation and not a true form of divine Ananda. The true divine Ananda in the physical has a different quality and movement and substance; self-existent in its essence, its manifestation is dependent only on an inner union with the Divine.....

Divine Love, when it touches the physical, does not awaken the gross lower vital propensities; indulgence of them would only repel it and make it withdraw again to the heights from which it is already difficult enough to draw it down into the coarseness of the material creation which it alone can transform....

Seek the divine Love through the only gate through which it will consent to enter, the gate of the psychic being, and cast away the lower vital error .
                                   

Sri Aurobindo Says", Bulletin, August 1965.

The Mother has already told you the truth about this idea. The idea that by fully indulging the sex hunger it will be finished and disappear for ever is a deceptive pretence held out by the vital to the mind in order to get a sanction for its desire; it has no other raison d'etre or truth or justification. If an occasional indulgence keeps the sex desire simmering, a full indulgence would only sink you in its mire. This hunger like other hungers does not cease by temporary satiation; it revives itself after a temporary abeyance and wants again indulgence. Neither sops nor gorgings are the right treatment for it. It can only go by a radical psychic rejection or a full spiritual opening with the increasing descent of a consciousness that does not want it and has a truer Ananda.
                           

    SRI AUROBINDO, Life-Literature-Yoga, 2ndEd., p.27.

As to the sexual impulse, for this also you must have no moral horror or puritanic or ascetic repulsion. This also is a power of life and while you have to throwaway the present form of this power (that is the physical act), the force itself has to be mastered and transformed. It is often strongest in people with a strong vital nature and this strong vital nature can be made a great instrument for the physical realisation of the Divine Life. If the sexual impulse comes, do not be sorry or troubled but look at it calmly, quiet it down, reject all wrong suggestions connected with it and wait for the Higher Consciousness to transform it into the free force and Ananda.

   letter of SRI AUROBINDO, in Mother India, Oct. 1967.

If she consents to marry , that would be the best. All these vital disturbances proceed from suppressed sex-instinct, suppressed but not rejected and overcome.

   A mental acceptance or enthusiasm for the sadhana is not a sufficient guarantee nor sufficient ground for calling people, especially young people, to begin it. Afterwards these vital instincts rise up and there is nothing sufficient to balance or prevail against them,-only mental ideas which do not prevail against the instincts, but on the other hand, also stand in the way of the natural social means of satisfaction. If she marries now and gets experience of the human vital life, then thereafter there may be a chance of her mental aspiration for sadhana turning into the real thing.

                                     "Sri Aurobindo Says", in Bulletin. November 1967.