I added a coworker on Facebook a few months back. I randomly one night sent him a couple music videos by an artist we talked about at work. The next day he took me aside and said he doesn't like to mix work and personal shit. Fast forward a month later, I upon happenstance hear from a couple of coworkers that they're friends with him on Facebook and message him all the time. We seem to be close at work. What do you guys make of this? I was kind of cold toward him today.