Why does your boyfriend's semen fall out of your vagina after sex?

Answer 1

What is leaking from the vagina is not the 'cum' all together. the semen, or the liquid that protects the sperm from the women's natural defences, have no reason to remain in the vagina once the sperm have collected into a place called 'the sperm pool' which holds the sperm until the cervix or the small opening that leads to the uterus opens and allowd the sperm to move in and find the egg. Thus the semen is leaked back out of the vagina, since it is not needed in the body anymore.