I don't know if anyone has said this but how are your pants fitting. Swamp crotch is irrelevant to holes in crotch of pants. It sounds like your pants don't fit good in the crotch region I don't know if you work and what you do for work but moving a lot in pants will rip them. Especially were your legs part.
As far as the junk sweat you have more than enough info.
As far as the junk sweat you have more than enough info.
