Boys have illusions or disillusion about girls in BD only because they have little chance to intermingle. To the boys, girls look like magic, Maya, and illusion more because they are segregated in BD. This too segregation creates more illusion.
Now, with sex education introduced, boys will see the girls in their proper perspectives and not through Maya and illusion. They will see girls as just another bunch of human beings whose physiques are equally clean or unclean as boys.
Note that those who study medicine and become medical doctors have little illusion about the body of women. With sex education, teenage boys will less dream about women's bodies.