I agree with Brasky in general. When I was 15, most of the girls I went to high school with did their best to look like they had stepped right off of some skanky magazine cover. It was actually quite frightening. And the fact that I live in Florida...land of the overtanned made it worse. A great deal of the girls had perfectly bleached blonde hair and/or highlights, and the ones who didn't looked some sort of hispanic, were goth, or were one of the 34 who just didn't give a shit. Kids are mean, man. Seriously. Growing up, every single flaw a young girl has is pointed out. Kids used to ask me the most horrid questions. Are your nails fake? Did you dye your hair? OMG where did you get that shirt?! Are you going to get braces? Ugh. Just remembering it makes me cringe. I was lucky, I never had acne or anything. That would have just been one more reason I wanted to kill people. My take on things now is that we are who we are, and eventually - if we're lucky, we will find another individual who appreciates that fully. Like Bill said, it takes a long time to get out of high school-mode.
And Taors, I don't think you not whistling at the ugly girls is scarring them for life or anything. Chances are good that if they are indeed ugly, they already know it.