Like "pillow talk", except you are NOT getting laid, no matter what. It's a faked intimate conversation between a cashier and the customer, even though the cashier could really care less about you or what's going on in your life. It's just a way to make the customer feel important and spend more money.
Cashier: So, are you spending the holidays at home with a girlfriend, or are you just going to relatives?
Customer: thinking she's coming on to him
. No, I'm not married, but I'll be staying at home.
Friend later on: Dude, she's not interested, she was just using some cashier talk to get you to buy that stuff.