It is a relatively common myth that penises can be too large.
As a professional, I can assure you they generally are not.
From time to time I receive a query from a girlfriend wondering if her potential new partner is perhaps too large. One of the perks of having an obstetrician and gynecologist as a friend is you can ask everything — and get informed answers.
I remind them that vaginas have been finely tuned by hundreds of thousands of years of evolution to stretch. If they are interested and if this gentleman is a safe choice, personally and medically, then break out the lubricant and have a ball. If it hurts, stop and give me a call — not immediately, but perhaps the next day.
It is also not uncommon for me to hear about penis size from people I barely know. Once I was out for dinner with my future ex-husband and some people I had never met. When the opportunity presented itself, the woman turned to me, just as I was taking a mouthful of pasta, and said, “We can’t have sex. His penis is just too big.”
Source: The New York Times