Withdrawal offers no protection against sexually transmitted infections. The men who use withdrawal must be able to know when they are reaching ejaculatory inevitability - the point in sexual excitement when ejaculation can no longer be stopped or postponed. The man withdraws his penis from the vagina before or when he feels he has reached the point when ejaculation can no longer be stopped or postponed. He ejaculates outside the vagina, being careful that semen does not spill onto his partner's vulva. Some men cannot tell when they are going to ejaculate.
Some men ejaculate very quickly, before they realize it.
Before ejaculation, almost all penises leak fluid that contains sperm that can cause pregnancy. Some men lack the experience and self-control to pull out in time. Some men have been known to say they will pull out, but they get so excited and carried away that they don't. Some men have been known to say they will pull out, but don't mean it. Not recommended for teens.