 The average age of first sexual intercourse in the United States is around 18 for males and around 17 for females, and this has been rising in recent years.For those teens who have had sex, 70% of girls and 56% of boys said that their first sexual experience was with a steady partner, while 16% of girls and 28% of boys report losing their virginity to someone they had just met or who was just a friend.Teens are using birth control (contraceptives) more today when they lose their virginity than they did in the past, and this is in part due to the AIDS epidemic.