There's a lot of ways to be a bad boyfriend. Some people are abusive, some people are unfaithful, and some people are just downright selfish and self-centered to the bitter end. On that last note, ladies and gentlemen, meet Christian, the bad boyfriend from Ari Aster's stunning sophomore feature Midsommar, who has become one of the love-to-hate-him hits of the year, a regular talking point on twitter, and undoubtedly, the cause of several arguments between couples who should have broken up a long time ago. Today, we've got a new exclusive behind-the-…