Hey I'm 14-15 and I'm worried about a big black line going from the tip of my penis to my anus, it has been there for a long time, I have been masterubating a lot. Is that why its like that? If you need pictures to verify what it is, just tell me. I didnt use to be there. My balls have the same color as the line, and it kind of connects to them. It doesn't hurt but I don't want it to stay there.
Thanks for the help