I'd say 11/12/13 is a good age to start, depending on the physical and emotional state of the boy. Like having a beer, watching a match or playing sports, PE is better when father and son do it together.
My son has been asking a lot about PENIS SIZE recently, which makes me think he's really curious about it. When he mentioned pumps and other devices I knew he's really serious so I started a research. I found a method that seems ideal for his age, it's called JELQ and since he's still developing...