Why do parents think of it differently when a teen girl's having and a teen boy is?

People still wish to think that their daughters are pure and innocent, sweet loving women. So to be that they try and be protective, while expecting their boys to be a man and go out and sow his oats. Which is weird as who the heck are they going to do that with mmmm. People still think of girls as in need of protecting as they are thought of as the weaker , which is not completely true. We all have ual desires at around the same age and continuing into ripe old age, hopefully.