Justin Bieber is no Christian Grey

Whose bright idea was it to offer Justin Bieber a role in the movie version of 50 shades of Grey? Unless he'd be playing a supporting or extra role, I just don't see it or get it. I can come up with a million reasons why it would FAIL horribly.
First and foremost, the 50 Shades series was written for moms and house fraus like me to turn up the sensual ambience for lack of a more graphic spin. And I am thirty-one. Justin Bieber is cute in a little brother or sad puppy kind of way for my generation. As I was reading all three books, not once did I picture Biebs or any other barely legal boy, which brings me to point number two. Is Justin Bieber old enough to even read the steamy manuscript? Are they planning on releasing a Disney version of 50 shades? Instead of S & M and safe words, maybe they'll do dance competitions and risqué make out scenes.
Justin Bieber is no Christian Grey. who could I see as Mr. Grey? Channing Tatum. Or if we could turn back the clock just a smidge for Christian Bale.
Who do you think should play Christian Grey in the 50 Shades movie?