A friend that I hadn't seen in a while, during which time I lost about 30 pounds, stopped by one day. In the middle of what he was doing, he suddenly took notice of the crotch of my Levis, said something to the effect of:
"Gee! Now that you've lost weight, your dick looks even bigger!"
Of course, there wasn't really any change in the size of my penis. It just wasn't competing with as much bulging fat.