I'm 13 and I can retract my foreskin with my hands when flaccid and erect, but it doesn't retract by itself at all, even when I have an erection. Do I need to be circumcised?
No, you do not need to be circumcised. The only time the foreskin retracts by itself is for those men who have a shorter foreskin. Yes, foreskins come in different lengths. For someone with a longer foreskin, the glans stays covered or partially covered. It doesn't interfere with sex becuase as the penis enters the vagina, the foreskin is pushed back. Thus, during sex, the foreskin rolls foward and back.