One of my new coworkers (very new, like maybe worked here a month now) went on a crusade to get another coworker of mine fired. She succeeded. I was friends with the other coworker and she did her job very well and we worked well as a team. I've since been very quiet and only talk to the new coworker about work-related stuff and only in short, direct sentences/statements. Seeing as she's a snitch that will run to HR at a moments notice, is this something I could get fired for? They can't force me to be friends with this person, right?