How to Deal With a Negative Neighbor

After leaving my apartment he started sending text messages that made me feel quite uneasy. When we made eye contact he licked his lips. I was shaking with fear. My friend saw how scared I was and when I told him what happened he went downstairs to confront Sam, pretend to be my boyfriend and told him to stop texting me. This is a story that happened many years ago when I was around eight or nine.