Buddhism

The man who became known as the Buddha (Sanskrit for "awakened one") did not seek to establish a religion or a dogma: instead, he taught how the human being can take advantage of their unique place in nature to become a fully developed and completely serene force of pure love and compassion. His famous "middle path" emphasizes the balance one needs between indulgence and avoidance: the very basis of this website.  His teaching eventually became dispersed into many schools of Buddhism, and within them all are many indications of the upright, healthy use of sexuality.

He should make love to his own woman [wife],
Visualising her as my embodiment,
And uniting lotus and vajra [sexual organs] in consummation
I [the Divine Mother] will give him enlightenment. - Candamaharosana Tantra