What is Perdunkadunk?
1.
When you're fucking a bitch all night-long, and your dick goes limp. You then turn her upside down and just dunk it in and out.
"When I was fucking Stephanie, by the time the third nut rolled around, my dick just wouldn't go back up. So I threw her off the bed, and slam-dunked it in. I gave her a perdunkadunk."