I suspect that this is much like any other part of a parent providing sex information to a child. The child can either get inaccurate or possibly dangerous information "off the street", from friends or from the Internet, or they can get accurate and reputable information from a parent.
If I had a son, I would rather tell him about Penis Enlargement as part of the full spectrum of information that he needs to know as a man. I think the angle of sexual health is a good one: "Son, this is a part of your body that needs care and maintenance to stay healthy, just like any other part of your body." No need to mention the enlargement aspect; send him to the right sources and he'll figure that one out on his own.
If I had a son, I would rather tell him about Penis Enlargement as part of the full spectrum of information that he needs to know as a man. I think the angle of sexual health is a good one: "Son, this is a part of your body that needs care and maintenance to stay healthy, just like any other part of your body." No need to mention the enlargement aspect; send him to the right sources and he'll figure that one out on his own.