Q: It cannot be denied that it is sexual desire that causes man to engage in coitus, even when reproduction is not the motive.
B: You ask about the biological sexual urge. That is impregnated in the ego mind body complex to facilitate reproduction, according to nature’s design. If the act did not involve pleasure, man would likely ask ‘Why should I give birth to children?’
     What is the highest joy man can know? It is the state of no-mind. Daily he experiences it in sleep. Only the yogi has experience of it in waking; for the Jnani there can be no question of experiencing anything. So, nature has seen fit to introduce this bliss of no-mind in the coital act.
       A moment before the commencement of the spasms that bring about emission of the seminal fluid, for precisely 1/128th of a second, the mind is removed. It is like a plate being exposed with a very quick shutter speed. The impression of the bliss tasted, leaves behind a strong craving for more such bliss in the mind. This is how men end up addicted to the act.

Bhagavan: People are so obsessed with and enamoured by mental activity that they imagine that by some special kind of mental activity, such as meditation, for instance, the Self can be duped into revealing Itself. It is not so. Only complete cessation of mental activity can reveal the Self. Giving up the personal self or the idea of the seekers existence, should, again, be volitionless and unconditional; it should not be driven by any motive.
 
If you feel tempted to ask for a formula for this also, know that there is none. You abandon the personal self not because you expect or anticipate or want Self-Realisation in return [in which case you never really abandon it at all – you only absurdly think that you do], but because in that very act of such abandonment, you discover for yourself, practically, as a DIRECT INSIGHT, that no such thing as the personal self ever existed and that no such thing could ever exist.