That is understood. Let's face it, a zipper and a pair of underware are going to make very little difference. What is going to make a difference is their attitude. Basically the word no - unless you are willing to chaperone them (which is a valid thing to do)

Basically, you have to raise your child up right. One reason I think the "fathers of daughters" are so paranoid is they remember exactly what they were like at the same age. Sigh