It is used to show the relation between 3 Siamese twins who were separated at birth and of which only two share the same birth date, but four years apart.
"Wow, Chelsea and Brion look really similar!" said some stupid idiot. Robin retorted "Yeah, they're my long lost Siamese twins, you stupid idiot. And our last name is probaby Kennhouseiguez."
by Robin Whitehouse July 2, 2007