As outwardly gross and morbid as it may appear,  one gets the message that the bond between conjoined twins is extraordinary and transcends everything.  When they were separated,  a certain distance and coldness  transpired that was not there before and the 2 persons longed to be one again. Something wrong happens along the way that prevented them  from being conjoined again but until the very end  they had each other and that I think was what truly matters.