Weird conversation with a girl! Help!?

I bought a jacket online, but it didn't fit so i went to the store and got store credit to find a perfect sizes. The cashier was a beautiful girl around 18. I gave her the jacket to get store credit. Later on around 30 minutes i was up in line and ended up with her again, but this time it was only me, her and a co-worker. A few seconds (around 30) the co-worker said "Isn't that the guy you were talking about early?" I got super red while she got red too. Don't know if she used her friend as a wingman? Any suggestions?