Can you tell when people are genuine?

I’ve met a couple guys recently.

One man (I met through a mutual friend) has a contracting company and I mentioned to him a few things with my roof. He did an estimate for me. I’m also a realtor and he is utilizing my services. THE THING IS now he wants to continue conversations and asks when I’m free and to let him know when I need anything if I ever need help with anything in general. I can’t gage what he’s doing and why.
Thoughts?
Can you tell when people are genuine?
Post Opinion