Motel Mix-Up Field Trip

Two teachers and two students on their way to a speech tournament find many of their plans thwarted when their van gets a flat and they have to stay in a motel. The teens have been dating for a while but have never had a chance to be alone, so they make plans to sneak out at night and finally get some alone time to consummate their relationship. They've got a night of passion planned. But what rooms are everybody in again?