How to Lose a Guy in Ten Days - Andie's Disappearing Drink
In the scene right after Ben and Andie go to the New York Knicks game and Andie has been asking for a diet drink because she's thirsty, Ben walks Andie to her cab. Right as Andie is at the cab she hands Ben her cup. They continue to talk and as Andie gets into the cab, she again hands him the same cup.
the How to Lose A Guy In Ten Days movie