I recently stayed at a clothing-optional men's B&B in Fort Lauderdale. One gentleman's member seemed perpetually pendulous; it was always girthy and it never shortened. Later, he casually mentioned he had penile implants so that he could perform "on demand."
Later during my visit, I had a session with a masseur/escort. When he greeted me at the door, his endowment was already turgid. During the massage, it remained plump and did not shorten (and during the escort portion of the visit, let's just say it did its job). I have never seen in person someone so erect for so long (90 minute session). Could this also be due to implants? He did not use a cock ring.