Trends towards earlier sexual experience are less pronounced and less widespread than sometimes supposed (in many developing countries the trend is towards later onset of sexual activity for women), but the trend towards later marriage has led to an increase in the prevalence of premarital sex.
Premarital sex is sexual intercourse engaged in by a person or persons who are not yet married. It is generally used in reference to young people who it is presumed can and one day will be married, but who are in engaging sexual practices prior to their being socially sanctioned within a marriage.
Different cultures have various views on the morality of sex outside of marriage. Some view marriage before sex as completely optional; others strongly disapprove of sex outside marriage.
— The Lancet