When you tuck your dick into your butt crack all day before a blowjob, and then yell “SWAMP COCK” and then smack her nose with your dong until she smells it
Swamp ass can occur during periods of intense physical activity. It is a condition where your ass becomes sweaty giving you the feeling that your ass is actually in a swamp. If not treated swamp ass can lead to a more serious condition called duck butter.
"Drain the swamp" originally means to get rid of the malaria-carrying mosquitoes by draining the swamp. Figuratively, "drain the swamp" means "to exterminate something that is harmful" or anything that most of the people hate such as corruption or government waste. This term is especially attractive for politicians during campaign.