The Kama Sutra
Chapter IX - Of the Auparishtaka or Mouth Congress
When, holding the man's lingam with her hand,
and placing it between her lips, the woman moves about her mouth,
it is called the 'nominal congress'.
When, covering the end of the lingam with her fingers collected together like the bud of a plant or flower,
the woman presses the sides of it with her lips, using her teeth also, it is called 'biting the sides'.
When, being desired to proceed,
the woman presses the end of the lingam with her lips closed together,
and kisses it as if she were drawing it out, it is called the 'outside pressing'.
When, being asked to go on,
she puts the lingam further into her mouth,
and presses it with her lips and then takes it out,
it is called the 'inside pressing'.
When, holding the lingam in her hand,
the woman kisses it as if she were kissing the lower lip,
it is called 'kissing'.
When, after kissing it, she touches it with her tongue everywhere,
and passes the tongue over the end of it, it is called 'rubbing'.
When, in the same way, she puts the half of it into her mouth,
and forcibly kisses and sucks it, this is called 'sucking a mango fruit'.
And lastly, when, with the consent of the man,
the woman puts the whole lingam into her mouth,
and presses it to the very end,
as if she were going to swallow it up,
it is called 'swallowing up'.
Striking, scratching, and other things may also be done during this kind of congress.
Vatsyayana moreover thinks that in all these things connected with love,
everybody should act according to the custom of his country, and his own inclination.
There are also the following verses on the subject:
'....Some women of the harem, when they are amorous, 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".'