When the crotch of a male's trousers or shorts has an sudden and unexpected rupture, causing "junkfall" in the wind.
This can include tightness of trousers, or looseness of shorts.
"Man, that guy the other night had such tight pants,that when he bent down to tie his lace he had junk explosion"
A bozo explosion happens when you go to an event where you know a couple of people in attendence in advance that are cool. You get to the event and find that there are more morons than there are cool people. The amount of Bozo's has exploded!
I was planning on going to Jill's party with Jessica. I arrived at the party and found the fucking idiots Ray, Thomas, and Seth there. It was a fucking bozo explosion!