Perhaps she wants a baby. Sex might be fun obviously, as are drink and drugs no doubt, but outside of a strong and well established relationship it can turn out to be disastrous. Not only can pregnancy and STDs result, but sexual intercourse can often be emotionally bonding (especially if regular or frequent), and when the strong friendship, mutual values and interests etc. are not in place this can prove emotionally confusing. Just read some of the questions here, or watch some of the daytime t.v. shows with very unhappy people who have had sex too soon and/or with the wrong person. It can also cost a girl her self respect and the respect of others (including future boyfriends).