ex giving me the creeps

I split from my ex about 5 years ago. I hadn't seen him for about 3 years and then I bumped into him at the local store where I shop with my mum. We chatted politely but since then he keeps showing up at the store he isnt even shopping he just seems to be looking for me. I now avoid shopping in the evenings incase I bump into him. I have been polite but the last few times I've been stand offish with him. my mum who feels sorry for him as he seems lonely leads the conversations and told him I was moving. He said I should tell him when I move and he will pop round with a bottle of wine this has creeped me out. I just don't know what to do. I live in a small area and feel uncomfortable going out.