When a man ejaculates the human body holds back to maintain the oval shape of the balls. When you shoot it all out, you create a vacuum, thus you have ball collapse. This often occurs in the presence of an excess of pussy.
"Jesus christ, back in the 70's when I was over Rick James house. I got so much ass I caught a case of Ball Collapse."
"Women be talking shit, men don't know nothing about pain! Women have babies! I be like bitch, YOU don't know about pain. I've had ball collapse. They don't have epidural for that." - Charlie Murphy