The definition as it has been explained through out the years is NOT to plessure a woman with one finger in her pussy and one finger in her ass. On the contrary it is TWO fingers in the pussy and One in the ass. It is most commonly explained to the unknowing with the following anechdote "Two in the pink, one in the stink"
Two in the pink, one in the stink
by Raoul Duke March 20, 2005