Say It Isn't So

The name of this movie is Say It Isn't So released in 2001-03-10 and it's main theme is Boy meets girl; boy falls in love and had wild, non-stop sex with girl; boy loses girl... when they discover they are brother and sister But when he learns that he's the victim of the ultimate case of mistaken identity, the lovesick young man -- whom everyone still thinks is after some taboo thrills -- must race across the country to stop her from marrying another man..