One person male or female that deposits an edible organic or in-organic object into their rectal cavity. Then another person male or female begins to chomp just outside of the rectum just at the same time as the object is being pushed out by the initial person that became the receptical. Thus the receptical, aka the person that just took the said object, organic or otherwise, becomes the living vending machine.
John is the vending machine, he just stuffed that girthy sausage into his ass, and now Paul is eating it, just as John shits it out.
by The one and only Datum bitches August 07, 2010