Creepy old guy? 16 year old girl?

Ok so i'm a 16 year old attractive girl and is aftaid that a guy that works with my mom may like me more than he should. He's 50 something and first added my on fb and then got my number off it and started texting me. He flirts with me ALOT but i heard he was the kinda guy who liked to stay hip with the stuff teens are into. It's gotten a little uncomfortable though. Most of the things he says you don't know how to react because what if he didn't mean it the way it makes you think? but then again why would he say something that could be questioned? Anyway over the past week i'd say it's gotten considerably worse and he wants to hang out with me or says he does. I haven't told anyone especially my mom because what if he doesn't mean the things he says like that? But on the other hand what if he means it in an extreme way? I need help...if i don't text him or message him back on fb he bugs me and bugs me until i do? Does anybody have advice or do you think he has bad intentions? btw him and my mom talk about me, it's not like it's a secret to her that he messages me but i don't think she knows he does as much as he does.