Dear Captain Awkward,
This one might be a little long, and I am frankly afraid there might not be any good solution for it.
My senior year in college, I shared a house with wonderful friends and an additional guy, A., who most of us didn’t know, but he was a friend of one of my roommates and we needed another person on our lease, so we welcomed him aboard. While him and I were never the best of friends, we got along okay for the most part, and developed an inside joke about how much we hated each other. Unfortunately, my “joke” hatred for him has since evolved into actual repulsion.
We graduated two years ago, and I moved out to another city, but I would occasionally see A. whenever I came back to visit other friends still in town, because we are part of the same social circle. It used to be fine until a year ago, when his girlfriend and him split up. Ever since, he has been making me and other women I know extremely uncomfortable.