How to nicely reject this guy?

[Taylor]

So while I was at work on Thursday, this guy started talking to me for a little, then he asked for my # and I gave it to him. He seemed pretty nice and cool, but now I wish I hadn't of given it to him.

He's 26 and I'm only 18, he even said before he asked ''wow i'm way too old for you haha'', but he still asked. I only gave it to him so we could talk as friends, but he flirts a lot and keeps asking to take me on dates and stuff.

He apparently has his own business, TV show, part time actor, etc. And based on his Facebook page, all that is true. But I just, I don't know, I'm not really interested in someone who's 26 .__. even as friends...

I've tried giving him hints that i'm not really interested such as taking hours to text back(most people would get the hint, but he doesn't seem to), he texts me goodnight and good morning, etc. He's a really nice, respectful guy so far, but again, not really interested in a 26 year old.

How do I nicely reject him? I'm almost scared to cause I don't know what type of person he really is and he knows where I work so all of this could go completely wrong lol. Anyways; any advice? Thanks!