There's a crazy old lady that gives sex advice on TV late at night that says the only way to know the size of a man's erect penis is to have him extend his little finger and thumb in opposite directions. The distance between the tip of his little finger and the tip of his thumb is the size of his hard cock. She says it's fool proof and works every time.
All these years I thought I had 6 inches and now I find out I really have 8!