CNE, also referred to as "Chronic nipple erections" are common symptoms of an arising condition called 'pinkbike'. Its also i direct side affect of mountain biking.
Alpha-Cinematography - I have been hanging on Pinkbike 2007-2009, geeking 2009-2011, and full time trolling from 2011. I think it is not pretentious for me to say that, I am a fkng mega troll. Yet I have never ever experienced CNE, despite my miserable condition, neither my nipples nor any other erogenic zone have ever gotten hard after seeing anything here... you may be the only one - give your doc a call