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
The unfortunate condition in which the penis has become so inflamed by the toxins of a woman's swamp pussy that the cock itself begins to change colors and ferment. The horrible odor emanated by the rotting flesh is enough to be noticed from a great distance.
Man: Dang, I got some mad swamp cock. I don't think I can make it to that job interview.
Woman: Sorry about that...
when you have sexualintercourse with a girl/man that's has swamp ass causing you to have mushrooms grow on your cock.
I had sex with my girl last night we had Shrek cosplay and it went Great because she had a swampy ass in turn giving me swampcock and a few mushrooms to grow down there.