By now, there's a good chance you've already seen Justin Bieber's penis. Even Bieber's dad talks about his penis online, which is both gross and a reminder of just how ubiquitous the Biebs-dong is these days. Anyway, if the Internet has taught us anything, it's that just because people have seen something once, that doesn't mean they don't want to see it again and again and again. See: cat memes, photos Ariel Winter's boobs for other examples. As you can see, Justin appears to be at full mast in this pic, so we can assume he was recently looking in the mirror.