A wardrobe malfunction in class

My calculus class at BYU was taught by a very smart, but very round, Harvard PhD.  He was whip-smart, but seemed uncomfortable interacting with the class.  Most days, he just turned his back to the class and silently did mathematical proofs while his 300 students silently took notes.
 
One day toward the end of class, however, he decided to break routine by engaging the class in a discussion.  It was a bold move to be sure, but unbeknownst to him, he was experiencing a wardrobe malfunction.  As I have mentioned he was a round man.  Round enough not to see that his boxer shorts were protruding 2 inches above his belt line.
 
Now, 2 inches of boxers is no real cause for alarm, but it made us all a bit uncomfortable.  It made him uncomfortable too, it seems, because he began to tug at it, and 2 inches quickly became 4 inches - and then 6 inches - speaking of calculus all the while.  I suspect he was trying to pull up his pants, but he kept gripping the band of his boxers instead.
 
The clock tick-tocked. . .  The audience, and certainly the professor, were growing more and more uncomfortable.  The tension was building.  A determined, two-handed hoist (accompanied by a grimace) turned the 6 inches of bright yellow boxers to 10 inches.  We the students were in a stunned state of awe, unable to avert our eyes from the quickly approaching train wreck.
 
The tension was unbelievable.  Something had to snap.  He gave an almighty heave and 10 inches became 16 (I'm not exaggerating).  And then it happened.  A skinny, pretty girl in the third row completely lost it, and exploded with roaring hyperventilating cackles, eyes bulging, finger pointing, and jaw unhinged.  The laughter lasted only 10 or 15 seconds while the rest of us sat as still as church mice.  She fell silent, turned crimson, gathered her books, and fled the room.
 
The room was utterly quiet for about 20 seconds, and then the bell rang.  I've never seen a room empty more quickly.