Sarah is Wearing Biff's Boxers

Ringing the doorbell, Biff waited impatiently for Sarah to open the door, occasionally looking around to make sure no one saw him. A moment later, the door opened. "Forget something, babe?" Sarah asked. Biff was about to say something, but the words disappeared as he saw what his girlfriend was wearing - boxer shorts, and nothing else. Her DD-cup breasts were fully visible. Anyone outside could see her, but she was acting like there was nothing out of the ordinary. "Hey, you okay?" she asked, seeing how he was looking at her. "Sarah, why are you wearing my boxers?" he asked, finally finding his voice.