Stay away from hemipenises, okay? I remember the old days of /f/, and I know what that leads to. It's all well and good when your mom lets you have two dicks, Billy, but then two won't be enough. You want more; you need more. When you get done mutating yourself and your mind finally collapses under the strain of processing input from your seventeen dickfingers and twenty-odd cuntmouths, that first doubledong will return to haunt your mind, in that instant, until the heat death of the universe. Once you grow a second dick, you're just a hop, skip, and a furry away from going full Corruption of Champions.
Friends don't let friends go full CoC.