Last month at my best friends birthday party we went for a walk around 11 at night to the convienience around the corner to get some smores' supplies and on the way back we started singing "Firework" by Katy Perry. We sang the line "'Cause baby you're a firework!" and off in the distance you could hear someone sing back "Come on, show 'em what you're worth" we continued singing back and forth until we got back to her house.MLIA.