Sexual intercourse or coitus or copulation is principally the insertion and thrusting of the penis , usually when erect , into the vagina for sexual pleasure , reproduction , or both. There are different views on what constitutes sexual intercourse or other sexual activity , which can impact on views on sexual health. Various jurisdictions have placed restrictive laws against certain sexual acts, such as incest , sexual activity with minors , prostitution , rape , zoophilia , sodomy , premarital and extramarital sex. Religious beliefs also play a role in personal decisions about sexual intercourse or other sexual activity, such as decisions about virginity ,   or legal and public policy matters. Religious views on sexuality vary significantly between different religions and sects of the same religion, though there are common themes, such as prohibition of adultery. Reproductive sexual intercourse between non-human animals is more often called copulation , and sperm may be introduced into the female's reproductive tract in non-vaginal ways among the animals, such as by cloacal copulation.
A survey, detailed in the August issue of the journal Archives of Sexual Behavior , reveals what motivates a person to have sex. In all, the researchers found reasons. Here are the top 50, first for women and then for men. Live Science. I was attracted to the person. I wanted to experience the physical pleasure.
D o you want to know why women have sex with men with tiny little feet? I am stroking a book called Why Women Have Sex. It is by Cindy Meston, a clinical psychologist, and David Buss, an evolutionary psychologist. It is a very thick, bulging book. I've never really wondered Why Women Have Sex.