The concept involves involuntary contractions in the genitals and an intense sensation way above normal level. An extended orgasm usually lasts for 15 to 30 minutes. Typically, an orgasm involves 9 to 12 contractions just imagine having thousands of involuntary orgasms.
The entire clitoris is sensitive, however, the left upper quadrant of the clitoris seems to be particularly sensitive. For, men it is the apex of their penis that's the most sensitive.