thumb|150px|left|Oral sex depicted in the Kama Sutra The Ancient Indian Kama Sutra, dating from the first century AD, describes oral sex, discussing fellatio in great detail (the Kama Sutra has a chapter on (or ), "mouth congress") and only briefly mentioning cunnilingus. However, according to the Kama Sutra, fellatio is above all a characteristic of eunuchs (or, according to other translations, of effeminate homosexuals or trans women similar to the modern Hijra of India), who use their mouths as a substitute for female genitalia.
thumb|150px|left|Oral sex depicted in the Kama Sutra The Ancient Indian Kama Sutra dating from the first century AD describes oral sex discussing fellatio in great detail (the Kama Sutra has a chapter on (or ) "mouth congress") and only briefly mentioning cunnilingus However according to the Kama Sutra fellatio is above all a characteristic of eunuchs (or according to other translations of effeminate homosexuals or trans women similar to the modern Hijra of India) who use their mouths as a substitute for female genitalia