are you speaking of the darkened skin on the underside of the penile shaft? if so I do have this and it appeared after starting pm. the strip extends from the glans and follows the testicle sack directly in the middle, how much further than that I cant say. Bryony made reference to this in some of his postings, and the title was strange mutated perineal region, there are some links about this in this posting. search byrony and you should find it. it seems once it appears it doesn't go away even with stopping pm. Hope this helps you.