Girls are starting out in HS and are well experienced way before they go to college...have you read 15 and 16 year old girls tweets??? Sexting is rampant today.
I have been out of HS now for 9 years and knew plenty of girls that had 8-10 partners before graduation...not all what you would consider "bad girls" far from it..vast majority were from good homes, most went to college and many on the honor roll. Lot of them earned academic or athletic scholarships.
Lot of naivety out there what is really going on. Parents don't want to believe their "little princess" is acting that way and keep their head in the sand.
That is the standard for female behavior of all ages on TV dramas and comedies now.
All the little pre-teens are learning.