A fly, in its simplest term, is a part of your pants, often where the zipper likes to hangs out at the bottom.
Flies also have the tendency to fall down around the person the wearer likes. Perhaps the fly gets a little inconfident and decides to commit suicide, thus pulling it down to its lowest level, a few inches below its previous state of living.
The fly has many ways of committing suicide, but it often is resulted by the AK-47 it carries in its pocket all the time. When the wearer (person wearing the fly) jumps on the trampoline or somewhere jumpy, the fly's AK accidentally shoots and kills the fly, often resulting in the fly becoming roadkill that makes it easier for it to fall over again easier than before.
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