A sexual act that most commonly occurs when a couple is engaged in doggy style sex. The male inserts a finger into the anus of the female, in an effort to initiate the Dirty Sanchez sequence. His plot is foiled however, when she buries her head in pillows out of sheer delight from the introduction of the finger.
I set out to give her a Dirty Sanchez for her birthday, but apparently all she wanted was a dirty ostrich.
by BDW June 11, 2006