I'm 13 and I can only pull my foreskin back when I'm flaccid. I think it might be something to do with a small piece of skin under the foreskin at the bottom I'm not sure what it's called but I think it connects the glands and the foreskin. I think I read a bit on this, and the people said that it breaks when you get older. I have no trouble with doing it when I'm flaccid (not erect) but it hurts when I try and do it hard. I masturbate quite regularly for my age. ( I think! ). Once a night maybe I'll skip a day out but then I do it the next day. Anyway thanks in advance.