I always call him to thank him for the packets
That's kind of you. Do you only call him to thank him?
Mostly just about other stuff, he's really cool to talk to. We talk for hours before I get tired of it.
It is good that you are spending time to get to know each other. It will make your relationship stronger to do that.
I'm happy that you like it, it's nice to get to know each other. I never really knew him.
It's wonderful you have created a new relationship through something so routine! I'm sure he loves spending time with you, and perhaps this can turn into something more.