It's not just teenage boys who fantasise about sex, but teenage girls also fantasise about sex in the same fashion, and better.
There is no difference between boys and girls when it comes to what types of sex they fantasise about, research reveals.
Also, there are no differences in the proportion of girls and boys who think that their sexual behaviour is influenced by pornography to a great extent.
"Among the most sexually-experienced adolescents, there was a perception that girls and boys are equally interested in sex which is a positive finding from the perspective of gender equality," explained Magdalena Mattebo from Uppsala University in Sweden.
Mattebo investigated the sexual experiences and pornography consumption of more than 800, 16-year-old Swedish upper-secondary school students.
It was unexpected that more than every 10th girl in the group stated that they watch pornography less than they would like to.
"It was also unexpected that there was no difference between girls and boys regarding fantasies about sexual acts," Mattebo added.
An equal proportion of girls and boys said that pornography influences their sexual behaviour.
The girls in the study were more sexually experienced than the boys when it comes to oral, vaginal and anal sex.
But there were no differences between them concerning various types of sexual partners such as buddy sex, one-night-stands and group sex, the study noted.
Based on traditional stereotyped gender roles, it was not surprising that the adolescents in the study had a more favourable attitude to boys having many different sex partners compared to the attitude towards girls having many different sex partner.
The study has been published in Journal of Developmental and Behavioral Pediatrics.