The Restaurant Effect

Subconsciously drinking water at a restaurant while the waiter refills the glass, resulting in a continuous need to use the bathroom throughout the meal.

This is most often seen in nervous people on first dates

Joe: I drank so much water before she arrived! And when she did, I had to leave to go to the bathroom four times during dinner! She probably thinks I'm so weird...

Steve: don't worry man, you were just suffering from the restaurant effect. It could have happened to anyone!