Prom

So there is a young man in his senior year of high school. Prom is coming up so he really wants to ask this one girl to go. He sets up a elaborate surprise and asks her to prom. To his fortune, she accepts. Fast forward a few months and the couple goes to prom. They get dressed up and ride a limo there. When they arrive they immediately hit the dance floor. After an hour or so, the couple decide to go to the bathroom. The boy goes in and out of the bathroom no problem. The girl however is waiting in line to use the bathroom. Once it's finally her turn she uses the bathroom and gets back to her date. She asks the boy to go get them some punch. The boy walks over to the punch bowl and there's no punch line. :)