Boys into the vagina a few times on the ejaculation, the glans is more sensitive, belongs to the premature ejaculation, may be due to physiological factors or pathological factors and so on. 1. Physiological factors: the first time sexual behavior psychological tension and anxiety can lead to premature ejaculation, long time excessive masturbation easily cause fast ejaculation. The head of the penis is more sensitive than normal, the degree of sensitivity of sexual stimulation during intercourse is too high, the threshold of ejaculation reflex is too low and premature ejaculation occurs. 2. Pathological diet: premature ejaculation is easy to occur in the case of chronic prostatitis and circumcision. (1) chronic prostatitis: the prostate gland will be congested during sex or sexual impulse, and when there is a serious prostate gland may make the gland secretion increase, sensitivity increased, thus causing premature ejaculation. (2) circumcision: when the foreskin is too long will make the glans sensitivity increase, so the phenomenon of premature ejaculation. Boys into the vagina a few times on the ejaculation of the more sensitive glans may also be caused by other reasons, it is recommended to go to the hospital as soon as possible to do the examination, according to the cause of the treatment.