The attendant comes out and begin's to pump gas into the first couple's tank. As he is doing this, he looks into the passenger window. "Hey, Hillary. We used to date in high school, do you remember me?" he asks. 

They chat for a few minutes, Bill pays and the first couple leaves. 

As they drive Bill is feeling very proud of himself and looks over at Hillary. "You used to date that guy? Just think what it would be like if you had married him," he says smugly. 

Hillary looks at Bill and shrugs. Then she replies, "Well I guess you'd be pumping gas and he would be the President."