Was it a good idea to tell my mom's boyfriend to tell his relative I'm not interested in him...?

3 days after visitng his family house on Christmas? There was this guy who I saw checking me out at the party and he kept asking me dumb questions. I could tell he liked me because while I was eating I could see him looking at me. It couldn't have been the food. Then he told me his newborn baby is... Show More

I don't plan on going back over there. He is not family