Mine is 6" and gets slightly wider and longer the more aroused I am, especially if foreplay is focused on it.
Too bad the penis doesn't continue to grow throughout life, like the nose and the ears.
Of course, a man's nose can be quite useful during cunnilingus (perhaps the subject of another thread), so at least something sexually useful continues to grow...
But I tend to agree with others who've said that if your partner is happy with how you use your penis
to enhance her sexual pleasure, that's all that really matters.
