I've got an unusual one.
In my early thirties I developed a strange
sore on my shaft. It looked as if the skin had
just beeen worn open. I went to the Dr and
they could not figure it out. They ran every
STD test possible and then they started
guessing (which i did not like).

In a few weeks the sore went away.
A few months later I discovered that
if I wore the cockring too tight and fucked
like a maniac, the too tight skin caused the
friction sore. Cute huh?