In Pennsylvania. The boys are now 19.
Brothers Stefan and Tyler Delp have spent every second of their lives together. They go to the same schools, play the violin in tandem, and recently sang a duet, "Put Your Arms Around Someone," at their school's spring hop. But the boys have never seen each other's faces except for some sleight of hand with mirrors or computers.
The boys, born at Thomas Jefferson University Hospital 19 years ago, are a rare set of identical twins, joined at the head so one faces forward while the other is turned backward. When they walk down the hall at the public high school where they take morning classes, one moves ahead; the other steps in reverse.