He hasn't replied to my fb message and friend request?

This guy at work who has been showing interest in me like staring at me and he smiles wen he does it too and then told his friend that he really likes me and will flirt with girls wen I was around to see my reaction. we nrver talk beyond our initial hi's in the hallway. So I finally told him on fb Dat I like alongside a friend request and he hadn't replied to any for 3 days but he has been online and has added other ppl have I been replaced