What is premature ejaculation (PE)? You might expect that this is an easy question to answer, but it depends on whom you ask. Masters and Johnson (1970), the founders of modern sex therapy, stated that a man has PE if he ejaculates before the woman reaches orgasm in 50 percent or more of their sexual encounters. PE is sometimes defined as a problem accomplishing a "normal" length of time between insertion and ejaculation. Studies have even defined PE by a specific amount of intercourse time: less than one minute, two, three, four, five, seven, or 10 minutes, each amount based on a different reason. Still others have proposed to define PE by the number of intravaginal thrusts: eight thrusts, 15 thrusts If You've Been Suffering From Premature Ejaculation, There's One Important Thing You Need To Know... Click Here!