It's a technique of supposedly using sex for spiritual enlightenment, from the Indo-Tibetan tradition. Basically, you keep delaying orgasm and supposedly can enter spiritual realms.
It has been very popular in the gay spiritual community through a workshop experience called The Body Electric, developed by Joseph Kramer. It is now offered to heterosexuals too. In the BE, people report having "full-body orgasms." I have referred a handful of nonorgasmic clients to it.