The formation and completion of a specific sexual act performed by six males, consisting of each of them standing so as to form a hexagon with a width no larger than 4 feet (this is obviously a very small hexagon). The male sextet masturbates furiously with the goal of simultaneous ejaculation.

The arching ropes of jism ideally initially hit the male counterpart (directly across the hexagon) in the face, then 2nd and 3rd spurts of the jism reach the waist, and finally the legs or ankles, thus ultimately and figuratively creating a parallelogram, or prism, of jism.
The wierdest thing happened at Tony's frat initiation. Apparently, there was a defector from the jism prism, so the 5 guys left had to cum twice.
by Billy Packer July 14, 2008
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