I’m 17 years old when my penis is not erect it’s 3.5 inches but when my penis is erect it’s 6.7 inches. I don’t know if 3.5 inches is good non erect I’m abit if ashamed of it. I’m coming up to 18 when my penis is erect some of my foreskin stays around the top maybe it might needs to grow/ might be a slow developer ( help me )