A group of 6 people all banging each other at once. It is the last level of sex on
the ladder of sex (2 people = secs, 3 = threesome, 4 = smash, 5 = mass orgy, 6 = shrekfest). It is the messiest type of sex, but also the most fun. Many people experiment with different types of shrekfests, including 6 person anal. People try to experiment with different genders, such as 3 male and 3 female, all male/female, all
transgender or all of some other type of made up gender. The term "shrekfest" comes from the shrek movies, aka
the greatest things mankind has ever made.