Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 3
Oneness with all [expressed through embracing and kissing]1 would then mean satisfying the sex-instinct with all – that would be a rather startling siddhānta, though there is something like it in the practice of Tantra of the left hand. But the left-hand Tantriks are more logical than you – for why should oneness, 
if it is to justify sex-expression, support only the lighter and not the cruder forms of love-expression? But is sex really based on love or sex-love based on sex-instinct? and is sex-instinct an expression of the spiritual feeling of the One in all? Is it not really based on duality, except when it simply seeks satisfaction and pleasure where there is no question of love at all? Is one attracted to a woman by the sense that she is oneself or by the fact that she is somebody else attracting one by some charm or beauty which one wants to enjoy or possess or simply by the fact of the difference from oneself, the fact of her being a female and not a male so that the sex-instinct can find a full field there?