Kamasutra portrays the artistic and divine pleasure of lovemaking in a tuneful way. Not only the union of male and female but also the oral congress with the eunuchs has quite a noteworthy description in Vatsayana`s Kamasutra.

There are two kinds of eunuchs, one that disguised as males, and the other as females. Eunuchs disguised as females imitate their dress, speech, gestures, tenderness, timidity, simplicity, softness and shyness. The process can be explained as the acts that are done on the jaghana or middle parts of women, are done in the mouths of these eunuchs, and this is called Auparishtaka. They live as a courtesan and gain their conceivable satisfaction, and their livelihood from this kind of sexual union.

Kamasutra affirms that eunuchs who disguised as males keep their desires undisclosed, and usually live the life of a shampooer. While shampooing a eunuch of this kind embraces and holds the thighs of the man whom he is shampooing, following to that he touches the joints of his thighs and his jaghana, or central portions of his body. Then, in case the lingam of the man is erect, the eunuch presses it with his hands and chaffs him for getting into that state. If after knowing the eunuch`s intention the man doesn`t allow him to do it, then without listening to him the latter does it of his own choice and begins the sexual activities.

According to Kamasutra, the eunuch, one after the other, does the following eight things:
The nominal congress: It is explained as when the eunuch holding the man`s lingam with his hand and place that between his lips and moves his mouth, it is called the `nominal congress`.

Biting the sides: Covering the end of the lingam with his fingers collected together like the bud of a plant, the eunuch presses or bites the sides of it and is called `biting the sides`.

Pressing outside: It can be explained as the case when the eunuch desired to proceed, presses the end of the lingam with his lips, and kisses it as if he were drawing it out, it is called the `outside pressing`.

Pressing inside: If the process continues and they are doing it in full swing, he again puts the lingam into his mouth, and presses it with his lips, this can be followed by taking it out, it is called the `inside pressing`.

Kissing: When, holding the lingam in his hand, the eunuch kisses it like the kissing of lower lip; it is called `kissing`.

Rubbing: When, after kissing it, he touches it with his tongue everywhere, and passes the tongue over the end of it, it is called `rubbing`.

Sucking a mango fruit: This is case when he puts the half of it into his mouth, and forcibly kisses and sucks it; this is called `sucking a mango fruit`.

Swallowing up: Lastly, with the assent of the man, the eunuch puts the whole lingam into his mouth, and presses it to the very end, as if he were going to gulp the whole thing up, and thus it is named as `swallowing up`.

Kamasutra also illustrates that some other things, which can be done during this kind of sexual union, are, Striking and scratching.

At the end of each case, the eunuch wants to stop the process but every time the man insists him to do the next one and in this way the whole course is done.

Unchaste and reckless women, female attendants and helping maids, i.e. those who are not wedded to anyone, but who survive on shampooing, also practice the Auparishtaka.

According to the Acharyas this Auparishtaka is the work of a dog, not of a man, it is a low practice, which opposed to the instructions of the Holy Writ. He also pointed that the man himself suffers by bringing his lingam into the mouths of eunuchs and women. But Vatsyayana says that the rule should be changed in case of someone staying with courtesan and it is not against to the Holy Writ. But he also says that the law prohibits the practice of the Auparishtaka with married women.

The people of Eastern India do not live with women who practice the Auparishtaka.

The people of Ahichhatra resort to such women, but so far as the mouth is concerned they don`t do any such action.

` The people of Saketa do with these women every kind of mouth congress; while the people of Nagara does every other thing accept mouth congress.

A verse of Kamasutra further defines this subject:
`The male servants of some men carry on the mouth congress with their masters. Some citizens, who know each other well, among themselves, also practise it. Some women of the harem, when they are passionate, do the acts of the mouth on the yonis of one another, and some men do the same thing with women. The way of doing this (i.e. of kissing the yoni) should be known from kissing the mouth. When a man and woman lie down in an inverted order, i.e. with the head of the one towards the feet of the other and carry on this congress, it is called the "congress of a crow".`

Vatsayana in his great work of art, Kamasutra says that in order to practice this sexual activity it is seen that courtesans leave men who possess good qualities, clever, etc. and become attached to low persons such as slaves or elephant drivers. Because though the practice is allowed by the Shastras the Auparishtaka, or mouth congress, should never be done by a learned Brahman, a minister who does the work of a state, or a reputed man. There is in fact no reason why it should be carried on. As for instance, the taste, the strength, and the digestive qualities of the flesh of dogs are used on medicine (used to heal the injuries of the lingam), which cannot be taken by the wise.