Excerpts:
People of the third sex are also classified under a larger social category known as the “neutral gender.” Its members are called napumsaka, or “those who do not engage in procreation.” There are five different types of napumsaka people: (1) children; (2) the elderly; (3) the impotent; (4) the celibate, and (5) the third sex.5 They were all considered to be sexually neutral by Vedic definition and were protected and believed to bring good luck. As a distinct social category, members of the neutral gender did not engage in sexual reproduction. This nonreproductive category played an integral role in the balance of both human society and nature, similar to the way in which asexual bees play out their own particular roles in the operation of a hive. In Hinduism there are no accidents or errors, and everything in nature has a purpose, role, and reason for existence.
... Rather, by behavior and as described in the Kama Shastra, the so-called eunuchs of ancient India engaged almost exclusively in homosexuality.
... Homosexual people are the most prominent members of the third sex. While appearing as ordinary males and females, their third-nature identity is revealed by their exclusive romantic and sexual attraction for persons of the same physical sex. Gay men experience the attractions ordinarily felt by females, and lesbian women experience the attractions ordinarily felt by males. Such people commonly exhibit other types of “cross-gender” behavior, but not always.