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.
Male A: "Yo, who's up for a shrekfest?"
Male B, Female A & B, Transgender A & B: "OMG ME YES THIS WILL BE AMAZINGNAEIONUIASRGBNIASRGS"
An event in which two or more guitarists shred like crazy. Shred fests may also contain different instruments as long as the core of the fest contains guitarists shredding like the world is about to end. Shred Fests are primarily seen in the heavier rock or progressive metal genres, and are usually played during concerts.