Here is one of the main sutras of Vigyan Bhairav Tantra, the main tantric scripture, commented on by OSHO.
Sutra number 48 says, “AT THE START OF SEXUAL UNION KEEP ATTENTIVE ON THE FIRE IN THE BEGINNING, AND SO CONTINUING, AVOID THE EMBERS IN THE END.” (When starting sexual union, keep your attention on the fire of the beginning, and continue so, avoid the embers at the end)
Here is the OSHO comment:
“Stay at the beginning. The initial part is more relaxed, warm. But don't be in a hurry to reach the end. forget the end completely. At the beginning of sexual union, he remains attentive to the fire of the beginning. While it is overflowing, do not be thinking about the release; remains with this overflowing energy. Don't look for ejaculation; forget it completely. I know total in this hot principle. Remain with your loved one or your lover as if they had become one. Creates a circle. There are three possibilities. Two lovers who come together can create three figures…, geometric figures. You may have even read it or even seen an old alchemical image in which there is a naked man and woman within three geometric figures. One figure is a square, another figure is a triangle and the third is a circle. This is one of the ancient alchemical and tantric analyzes of the sexual act. Normally, when you are having sex, there are four people, not two, and this is a square: there are four angles, because you yourself are divided into two…, the part you think and the part you feel. Their marriage is also divided in two; there are four people. Two people are not coming together; four people are coming together. It is a crowd and, truly, there can be no deep union. There are four corners, and the union is simply false. It looks like a union, but there isn't. There can be no fellowship, because the deepest part of you is hidden and the hidden part of your loved one is also hidden. Only two heads are coming together, only two processes of thought are joining, not two processes of feeling. These are hidden. The second type of union can be like a triangle. There are two: two angles at the base. During a sudden moment, they make one, like the third angle of the triangle. For a sudden moment, they stop being two and make them one. This is better than a square union, because at least for a moment there is unity. This unity gives you health, vitality. You feel alive and young again. But the third is the best, and it is the tantric union: they come back in a circle. There are no angles, and the union is not just for a moment. The union is truly timeless; there is no time in it. This can only happen if you are not looking for ejaculation. If you are looking for ejaculation, then a triangular union will become, because the moment there is ejaculation, the point of contact is lost. It remains at the beginning; don't go to the end. How to remain in the beginning? You will have to remember many things. First, don't consider the sexual act as a way to get anywhere. Do not consider it a means; it is the end in itself. It has no end; it is not a means. Second, don't think about the future, it remains in the present. And if you cannot remain in the present at the beginning of the sexual act, then you can never remain in the present, because the very nature of the act is such that it is bold to the present. It remains in the present. Enjoy the union of two bodies, two souls, and merge the one into the other, dissolve the one in the other. Forget you're going anywhere. Stay in the moment without going anywhere, and found yourself. Heat, love, should become a situation for two people to merge into one another. So, if there is no love, the sexual act is a hasty act. You are using the other; the other is only a means. And the other is using you. They are exploiting each other, they are not merging each other. With love I can merge you. This fusion at the beginning will make you understand many things. If you are not in a hurry to finish the act, little by little the act becomes less and less sexual, and more and more spiritual. The sexual organs also merge into each other. there is a deep, silent communion between two bodily energies, and then they can remain together for hours at a time. This union becomes more and more profound as time passes. But don't think. It remains in the moment, deeply melted. it becomes an ecstasy, a "Samadhi", cosmic consciousness. And if you can know this, if you can feel and perceive it, your sexual mind will become non-sexual. deep brahmacharya, celibacy, can be achieved. one can achieve celibacy through this! This seems paradoxical, because we always think that if a person has to remain celibate, he must not look at the other sex, he must not join with the other sex. You must avoid it, escape. Then there is a very false celibacy: the mind keeps thinking about the other sex. And the more you escape from the other, the more you have to think, because this is a basic, profound need. Tantra says don't try to escape; there is no escape possible. Rather, it uses nature itself to transcend. Don't fight; accepts nature to transcend it. If this communion with your loved one or your lover goes on without thinking of ending it, then it can remain at the beginning. Excitation is energy. You can lose it; can reach a climax. Then the energy is lost, and this will be followed by a depression, a weakness. It may seem like a relaxation, but it is negative. Tantra offers you a dimension of higher relaxation that is positive. The two lovers, merging, give each other vital energy. they become a circle, and their energy begins to move in a circle. they are giving each other life, renewing life. No energy is lost. Rather, it gains more energy, because through contact with the opposite sex, each of its cells is stimulated, excited. And if you can merge in that excitement without bringing it to a climax, if you can remain at the beginning without calming them, simply remaining warm, then two "warmths" will join and you can prolong the act for a very long time. Without ejaculation, without throwing energy, a meditation becomes, and through it they come back total. Through her, her divided personality is no longer divided; stays together. Every neurosis is a division. If you are "united" again, you become a people again: innocent. And once you know this innocence, you can continue to behave in your society as it requires. But now this behavior is just a representation, an act. This is not involved. IS. a requirement as soon as it does. But that is not it; it's just acting. You will have to use unreal faces because you live in an unreal world; otherwise the world will crush you and kill you. we kill many real faces. We crucified Jesus because he started to behave like a real man. Unreal society will not tolerate it. We poisoned Socrates because he started to behave like a real man. behave as society requires; do not create unnecessary problems for yourself and others. But once it knows its real being and the totality, the unreal society cannot become neurotic; you can't go crazy.