Hourglass effect 

A side effect when the act in which two or more people engage in anal sex occurs. When a man inserts his penis into another's asshole, and then the person squeezes said asshole, the penis is then contorted into an hourglass shape. This is the hourglass effect

Bill: "Stop squeezing your asshole! You're givin' me in hourglass effect!"

Hourglass effect by Mike November 13, 2003

Hour Glass Effect 

Where a man goes to put a condom thats too small on and it makes the penis look like an hourglass.

My circulation was cut off because of the hour glass effect.

Hour Glass Effect by Brent H. (Lol Nicole) August 6, 2008

Hour Glass Effect 

When a guy goes into cold water and his ballsack shrinks around his testicles, resembling a sideways hourglass.

At the beach, the water was so cold that I experienced the hour glass effect.

Hour Glass Effect by TheSavageSquid June 1, 2010