Where a group of males get together, to masturbate themselves, but in front of each other.
Where a group gets together, usually to have a contest, to see who can either cum the fastest, or who can cum the most, out of the group.
This generally includes three or more males.
It can also include to see who has the biggest penis, before and after ejaculation.
Where a group of males, three or more, gather to have a contest. The 'game' can have a singular purpose or multiple purposes, in which the group will determine who can ejaculate the most, who can reach ejaculation the fastest, among those gathered.
Usually the participants sit around in a circle, hence the term 'circle jerk' though not required.
Added 'contests' can be to determine whose penis is the biggest, generally referring to the length, though at times girth can be taken into account.
In can also include determining who can remain the most erect after ejaculation.
Usually this is done by each individual, without any of the participants engaging in touching of the other members sexual organs.
In Pornography, it is the opposite, where the participants engage in touching, in even helping each other to measure, to ejaculate.
Practice (Associated Acts): It can also be a form of playing a trick on some unsuspecting individual, or as a form of initiation ceremony into a group, fraternity, or gang (non criminal).
The joke is that the lights are turned off, or all members are covered by a large blanket or such, where everyone is supposed to then take their penis out, and masturbate.
When one is about to ejaculate, they are supposed to call out, so as to be declared the winner, however the unsuspecting person is actually the only person masturbating. So that when he calls out, the blanket is removed or lights turned on, to show the others are still fully clothed, and not playing with themselves.
It can be used to humiliate a person, and generally occurs in cliques at summer camps, or at sleep overs of teens considered minors.
Noteworthy: In some instances, Circle Jerks are considered an extension of the male's desire to compare their sexual prowess with other males, in a non sexual way, that establish their dominance.
In short, that they are more adept at certain sexual activities, than their counterparts, either in the semen they produce, the speed in which they can produce it, or in penis size.
Part of the natural desire of the male to be the dominant force among other males.
Can be used as a form of determining who has a better sexual prowess, or endowment, among competing males.
Additionally, is used as an ice breaker, or as a tension breaker, among persons wanting to engage in sexual relations with all parties involved.
Used in pornography videos, to end a group sex session, or to precede a more involved group sex session.