 When Eric s cousin, Penny, comes to visit, Eric has fun telling the gang stories of how he pulled pranks on her when they were kids. But when Penny shows up, Eric is shocked (and disturbingly aroused) at the fact that she s incredibly hot. Eric becomes more confused when Penny begins hitting on him. When he confronts her, Penny explains to Eric that she s adopted and they re not really cousins. But the joke s on Eric when he finds out it was all just Penny s plan to get back at him for all the pranks he used to pull on her.