Why does he look at me?

Sometimes I see this cashier guy looking at me while I'm talking to this guy. I used to talk to him all the time. He and I went out and hooked up once. But I befriended a new guy who works as a cashier at the same store and now I talk to him. And sometimes I see him looking at me I still talk to him too though...
Why does he look at me?
Post Opinion