So I was sarging this girl at a store and all of a sudden some random girl walks in between us and joins the conversation (about what I should buy). I started talking with this random girl who was with what appeared to be her boyfriend (who was just standing quietly and staring ahead). The girl I was sarging noticed that I was talking to the rando, so she proceeded to get some things then walk away. The rando was actually better looking, but her boyfriend was standing right next to her! I asked her where she worked, and she told me. I asked another question (like how far the place she worked was from the store I was in), but she didn't really answer it. When I thanked her for her advice, she wished me luck while staring ahead at the items on the aisle.

What should I have done differently?