It all starts after you've jacked off: you have put your pants back on, and are minding your own buisness when you get this cold slimy sensation/tingling down your left leg. Then you realize that your dick has just coughed up another drop of cum, and its slowly crawling down your legs. You start to limp, trying to make sure it doesn't stain your pants, while acting normal. You can't do anything. Your stuck. You've just become a victim of a leftover koppel.
"oh dude i was jackin it between math and latin and i thought i was all juiced out...but no, half way through latin i fell victim to a leftover KOPPEL."