Back to the original spirit of this thread
John and Mary, come together in matrimony become 1.
(because of an issue or 2 could be barreness, sickness, incompatible sex drives etc)
John and Mary=1 decide to come together in matrimony with Jill for a specific reason.
So now John, Mary and Jill are still 1 in matrimony

Wheres the damn problem

?? So even bibilically speaking they are one in spirit et al
Mary knows who Jill is, Jill Knows who mary is and John is humping his brains out. Is there a possibility that our ancestors had it right the first time??
Wheres that damn time machine??