I just started a new job a couple of months ago and I found out that an ex also works there. We talked for about a month, were intimate, and he ended things by ghosting me. He stopped talking to me about a year ago. Tonight I went out with some friends and he was at the same bar so he came over with his friends and he started talking to me. He kept asking if we met before because I "looked familiar" and he specifically asked me where I work. I just felt very awkward and made my friends leave. Why would he do that? Just to mess with me?