Sometimes I make up appointments or phone calls or commitments to limit people I don't want to talk to annoying me. There's a guy at work I don't like who's similar. Any time I engage with him, I'm super nice but always warn him "I have a call in five minutes" or "I have to head out in ten minutes for an appointment." Then if necessary, I'll interrupt him "I'm really really sorry but I really have to run or I'm going to be late". Is this an option?