How do you get a guy who's utter bad news off your mind?

So there's this guy from one of my cles who I find myself drawn to for some stupid reason unbeknownst to me because he's a total and complete jerk...it's pretty easy to ess that by just hearing him talk with the cruel things he says about people. He's a Brit, so I get that he has a different sensibility than me, but like he thinks it's hilarious when a 13 year old commits suicide and talks about how much he hates people in our cl who never did anything to him. Even if he were to ask me out, I'd never date him because I mean, let's be honest, that would NEVER turn out good with a guy like that. But I still keep finding myself checking his Facebook every 10 minutes to see what he's doing like a giddy 12 year old. It's utterly pathetic. I'm too old for stupid crushes lol. How do you get someone off your mind who you know is just bad news?