Thinking about it, and from my own experience as a teen. Girls are often pressured into having sex by their boyfriends, before they are ready. They may consent, but it is very close to being rape, and very dodgy ground. This could also be the start of the pattern that leads some men to carry on through life with no respect for women. I do think that the earlier both boys and girls are taught about their rights over their bodies, the better.
More than ever these days, girls dress in a much more overtly sexual way, but the message needs to be given to boys that this is not an invitation for sex. Looking "sexy" does not mean you want sex, or that you are offering sex.