Is this normal?

Whenever I give a guy my number he starts trying to text me all day long. I love a little comment here and there, but conversational texting only goes so far. And then I feel like I have to respond to be polite because he's a nice guy and all, but I seriously can't do this all day every day.

Any advice for a girl on how to stop this my lovely PUA artist friends?

I'm 22, this isn't middle school anymore.