Building a better bad boy

We all love a bad boy. We either want to be one, or tame one. He's the fantasy feature of literature and he never, ever goes out of style. He is style.
So, how do we spot one? What are the key credentials in acquiring bad boy status? Let's have a look at a few examples and qualifications.
1. He's gorgeous. Well, that's a given. He's an alpha male who leads the pack or the lone wolf. Nothing shouts ego like turning up at a party alone, and still being centre of attention. Yes, I mean you, Mr.Dar...