I have heard and read numerous reasons but I think it is still unclear. Tantric sex seems to be a part of it and not the kama sutra. The word Tantra means "to manifest, to expand, to show and to weave." In this context, sex is thought to expand consciousness and to weave together the polarities of male (represented by the Hindu god, Shiva), and female (embodied by the Hindu goddess, Shakti), into a harmonious whole.
— Dr. Mike Mellum, January 18, 2012

Thanks for all your good photos, when I was there I was amazed at all the erotic carvings, but the guide told me, they were intended to draw the young people into the temple (or mosque?) to worship!!
— Eleanor Robb, January 17, 2012