Say It Isn't So Movie (2001) - Chris Klein, Heather Graham, Sally Field

Say It Isn't So Movie Trailer (2001) - Plot synopsis: Jo and Gilly date. They find out they're brother and sister. Jo moves away. Gilly finds out that he's not Jo's brother and that Jo's getting married. Can he stop the wedding in time?
Director: J.B. Rogers
Writers: Peter Gaulke, Gerry Swallow
Stars: Chris Klein, Heather Graham, Orlando Jones , Sally Field, Richard Jenkins