Reading today on Artistdirect.com I found out that:

Bieber fans refer to Justin Bieber's penis as "Jerry,"

The singer recently told Q that he doesn't like fans under the age of 13 making comments about his junk because they are too young. 

Quote of the article:

"I don't really agree with 12-year-olds talking about those inappropriate things," he said. "I just think the younger people are, the closer the parents should watch out over the kids. But once they turn 13, it's easier because they're going to learn that stuff anyway." 

So at 12 no talking about "Jerry", 13 all good to talk about "Jerry" How about we just not talk about Bieber's junk.. EVER!