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1.
When the humidity in a male's trousers causes one or more sides of the sack to stick to their inner legs causing extreme discomfort. This occurrence usually results in the individual peeling the sticky sack from their leg (crossing their fingers that sap sack will not return).
Uhh, I've been sitting down for so long, I got a real bad case of sap sack
by whackpack February 26, 2007