Tantra is an ancient Hindu practice which mixes meditation and non-orgasmic sex to attain a state of perfect bliss.
The ritual is based on activating the human energy centers or chakras, which hold the potential to reach 'cosmic awareness'. The human body is thought to have 6 main chakras (base of spine, near navel, near heart, near throat, between brows and most importantly genitals) each of which represents a gateway to higher energy. Tantric rituals emphasize the need to open up these energy points in order to harmonize the flow of energy throughout the body to help achieve an elevated state of sexual awareness.
A common term for female vampires who feed exclusively through sex is Succubus, a word which originally denoted a medieval demon who was believed to rob men's sperm by visit them in dream and tempt them into sexual misconduct.