The origin of this problem is the ass crack. Once sweaty it begins to get itchy, like you did not wipe well enough. After it gets unbearable you begin to scratch like crazy, and shortly thereafter your whole ass feels like one big cactus has spanked you for hours.
John and Bryan were walking home at a fast pace; Due to the intense friction, John's ass crack began to sweat and itch. Result, Swamp ass.
A condition caused by excessive moisture build up on one's ass, creating a very uncomfortable and disgusting situation in anal region.
After Marcus and Antonia were done frolicking about they all had a terrible case of swamp ass.
When you get that sweat in your backside area and your pants/shorts are sticking to you.
"Its so hot in here, I'm getting swampass"
when your ass gets so sweaty, there is so much sweat it gets a little soapy, and your ass is drenched in sweat and your ass cheeks might even be pruned
you could be sitting at a baseball game, just chillin with your friends, its a little humid you notice, suddenly you have to go to the bathroom, you stand up and your friends, family, girlfriend or boyfriend sees that your ass has two wet spots near the crack, one might say you have swamp ass or just imply that they are scared an alligator from your assmarsh might attack them
An unfortunate condition that results in extreme discomfort to ones anal opening. This condition is usually brought on by excessive perspiration, excessive friction / movement and incomplete anal paper work. Can also be brought on by liquid or solid content flatulence and excessive bowel movements.
A runner with diarrhea will experience swamp ass on warm summer days.
WHEN ONE'S ASS SWEATS UNCONTROLLABLY AND THAT SWEAT BEGINS TO SOAK THROUGH THEIR UNDERWEAR AND PANTS.
I HAD TO WAIT IN THE DRIVE THRU WITH NO A/C AND HAD THE WORST CASE OF SWAMP ASS EVER.
A boggy, stinking mess that inhabits ones genital area.
Do you smell that??! Smells like swamp-ass in here!