Right away, Sister had to screw things up. "Potato salad!"
"No. I'm tired. Let's just get out of here."
"We need potato salad. Please?"
"We're not getting potato salad!"
"We have to get potato salad!"
"No!"
He started walking away. A man walked between him and sister, making a bee-line for a watermelon display. "You gotta get potato salad," the man said as he passed.
He turned on the man, pointing an accusatory finger. "You stay out of this!"
Needless to say, they got potato salad.