A condition endured by fat people who do not clean properly between their thighs and their pelvic area. The condition is exacerbated by hygienic neglect, heavy walking, and sloppy masturbating. Swamp crotch produces one of the worst smells known to mankind - maybe even the worst. Worse than burnt popcorn, Mexican food-induced flatulence, and a recently run-over skunk combined.
Shawn should wash between his legs in the shower more often. He's got a hellacious case of swamp crotch.